Laser Measuring Tools: specifications, types

General type of device.

Modern levels differ primarily in their operating principle: they are optical(traditional or digital) and laser(conventional and rotary). At the same time, the specific specialization depends on the principle of operation - laser and optical devices differ in purpose and application. In turn, the main function of rangefinders is clear from the name - determining distances. The difference here also lies in the principle of operation: most modern rangefinders are laser, but there are also more specific ultrasonic devices.

Here is a more detailed description of each of these varieties:

— Optical level. Levels have a traditional design - in the form of a kind of specialized telescope mounted on a tripod and supplemented with measuring scales (including in optics, in the operator’s field of view), as well as devices for horizontal alignment (compensators, levels). Such devices are used to determine height differences using the so-called geometric leveling method, for which leveling rods are also used - special strips with measuring scales installed vertically. And the general principle of this method is as follows: the operator points the level’s telescope, set horizontally, at the vertical leveling staff, and determines...which mark on the staff is opposite the main “sighting mark” of the level - this mark will correspond to the actual height of the device. More information about this method, including specific measurement techniques, can be found in special sources. Here we note that optical levels are excellent primarily for working in large areas of open areas; they are used mainly in such fields as geodesy and cartography. But for work where one has to deal with relatively short distances (primarily construction in small areas), such devices are poorly suited; However, they are quite complex and expensive, especially compared to laser devices. So, relatively few optical levels are produced nowadays.

— Digital level. In fact, it is an advanced version of the optical levels described above. Externally, they differ primarily in that instead of a regular telescope, such devices are equipped with a digital camera that displays the image on the screen on the control panel. Such levels are used in the same way as “regular” optical ones, but the operating procedure itself is automated and supplemented with a number of advanced functions. Thus, in most models, the operator does not need to manually count the slats, record the results and carry out calculations - the device itself recognizes the recorded marks, stores them in memory and processes the received data, displaying the final result. It is often possible to save information to a memory card or other media, copy it to a PC, or even connect the level to a laptop and use special software (for example, mapping) directly during measurements. On the other hand, such opportunities are not cheap: digital levels are several times, or even orders of magnitude, more expensive than traditional optical ones. So, in general, devices from this category are high-quality devices, designed primarily for professional use - when you often have to deal with large volumes of work, in light of which speed and ease of data processing are of key importance.

— Laser level. A kind of laser projectors that display marks on walls and other surfaces - usually in the form of lines, but there are also models with a dot function (for more details, see “Point projections”) or even only dot ones (see “Purpose”). A classic laser device actually combines the functions of a level and a building level: it can be used both for the above-described geometric leveling using slats, and for constructing planes and marking lines (some models are equipped with mechanisms that allow you to arbitrarily select the angle of inclination). Such devices are well suited for working at short distances, including indoors; and thanks to their relatively simple and inexpensive design, they are very popular, especially in construction. At the same time, we note that some models can have a fairly significant measurement range - up to 50 m on their own and up to 150 m or more using special receivers.
We emphasize that this paragraph includes traditional laser levels, in which the mark line is formed by scattering the beam with a special prism. Rotary models that operate by rotating the emitter are included in a separate section and are described below.

— Rotary level. A variation of the laser levels described above, in which the plane is “drawn” not due to the scattering of the laser beam in the prism, but due to the rapid rotation of the emitter. As a result, the trace from the beam merges into one continuous line for the eye. Rotary levels are usually not cheap and most of them are professional devices designed to work on large areas. The measurement range without a receiver is usually several tens of meters, and with a receiver - up to several hundred. In light of this, when using such devices, you need to be especially careful about observing safety rules - getting a powerful laser beam into your eyes can cause harm to your health, and even the reflection of a laser “bunny” from some surfaces often causes discomfort. So, it is highly advisable to use safety glasses or masks in the operating area of the rotary device.

- Laser rangefinder. Devices for measuring distances using a laser beam. The key advantage of such devices over rulers, tape measures, etc. is that there is no need to move during the measurement process - just place the device at the starting point and point the beam at the object, the distance to which you want to determine. At the same time, the range of action in many models reaches 100 m or more, and the error does not exceed a few millimeters, or even fractions of a millimeter. In addition, modern laser rangefinders can be equipped with various additional functions such as automatic calculation of area and volume, summation of distances, fixation of minimum and maximum, etc. The disadvantages of such devices include reduced efficiency in the presence of fog, heavy dust or other similar contaminants air, as well as difficulties in measuring distances to glass and other transparent objects that transmit the laser beam rather than reflect it. However, these moments are not so often critical, and in terms of performance characteristics, laser devices are noticeably superior to ultrasonic ones. Therefore, this type of rangefinder is the most popular in our time.

— Ultrasonic rangefinder. Range finders using ultrasound; In such devices, a laser is also often installed, but it is intended solely for precise pointing at the desired object and is not used for measurements. In any case, rangefinders of this type are good because their effectiveness practically does not depend on the purity of the air and the type of surface on the object being measured: ultrasound works perfectly through dust, smoke, fog, etc., and is also reflected perfectly from glass and other transparent materials. laser materials. On the other hand, in terms of “range” and accuracy, such devices are noticeably inferior to laser ones: the measurement range in them does not exceed 15 - 20 m, and the error is calculated not in millimeters, but in percentages - usually about 0.5 - 1% (which, for example, at a distance of 10 m corresponds to an actual error of 5 - 10 cm). As a result, rangefinders of this type are much less common than laser ones these days.

General purpose of the device.

This parameter is indicated for models that have a clear specialization - these are mainly laser levels, including rotary ones. Among such devices, there are the following application options: for the 360° area, only for point projections, for the floor and for pipes. Here are the features of each of these varieties:

— For 360° area coverage. A full circle, 360°, by definition covers all rotary levels (see “Type”). However, such specialization can also occur in “regular” laser models. In such devices, full 360° coverage is achieved in other ways - usually by the presence of several emitters, each of which covers its own sector, or a special prism that scatters the beam from one emitter over a full 360°.

- Point projections only. Levels with this feature do not form marks in the form of lines during operation and “draw” only points. At the same time, in the simplest models there is only one point projection, but devices with several marks (up to 5) are more common. In any case, such devices are intended for relatively simple work where there is no need for marking along lines.

- For the floor. Levels designed for working with floors - screeds, laying coverings, etc. A common feature of such devices is a fairly wide base, which allows, in fact, to place the device di...rectly on the floor. But the specific design and operating features of levels of this type may be different. Thus, devices with a characteristic layout are quite popular - with two vertical projections intersecting at an angle of 90° (some models provide two more projections directed in opposite directions from the main ones). Such a device can be used not only on the floor, but also on walls: if you press its base tightly against a particular surface, it will form two clearly perpendicular lines on it. In the case of floors, this can be convenient, for example, when laying tiles.
Another common type of floor level is devices designed to detect unevenness. To do this, use a line formed on the floor using a vertical projection. During operation, a level placed on the floor and aligned horizontally rotates around a vertical axis, and the line “scans” the floor; when it hits a ledge, it becomes uneven. Note that in the simplest models, such a “scanner” uses only one projection, but there is also a more advanced version - a line created by two projections at once. Such a pointer, when it hits an uneven floor, is divided into two separate lines - this is much more noticeable than the deviation when using a single projection.

- For pipes. A rather rare type of specialized laser levels are devices for laying pipelines. They are used, in particular, in the construction of water supply, sewer and stormwater systems. Pipe levels most often have a characteristic cylindrical shape, with a handle at one end and a point laser emitter at the other. They are installed horizontally on special legs (the kit usually comes with several sets of such legs, varying in height); the design usually has a self-leveling mechanism with quite extensive capabilities; and the necessary measurement accuracy is ensured by a target with special markings. Such devices allow you to at least accurately lay horizontal lines, and many of them also allow you to work with corners.

The range at which the device remains fully operational without the use of additional receivers (see below); in other words, the radius of its action without auxiliary devices.

In some models, a range may be specified that shows the minimum ( 3 cm, 5 cm) and maximum measurement ranges. But in most cases, only the maximum value is indicated.

The specific meaning of this parameter is determined by the type of instrument (see above). So, for optical levels, the measurement range is the greatest distance at which the operator can normally see the divisions of a standard leveling staff. For laser levels, this parameter determines the distance from the device to the surface on which the mark is projected, at which this projection will be easily visible to the naked eye; and in rangefinders we are talking about the greatest distance that can be measured. Typically, the measurement range is indicated for ideal conditions - in particular, in the absence of impurities in the air; in practice, it may be less due to dust, fog, or vice versa, bright sunlight "overlapping" the mark. At the same time, tools of the same type can be compared according to this characteristic.

Note that it is worth choosing a device according to the range of action, taking into account the features of the tasks that are planned to be solved with its help: after all, a large measurement range usually significa...ntly affects the dimensions, weight, power consumption and price, but it is far from always required. For example, it hardly makes sense to look for a powerful laser level at 30-40 m if you need a device for finishing work in standard apartments.

The longest measurement range provided by a laser level (see “Type”) when using a special receiver with a photocell.

Thanks to its sensitivity, such a receiver is able to respond even to a weak laser beam, the mark from which is no longer visible to the naked eye; At the same time, the area of the photocell is quite large, and special indicators make it possible to determine the exact position of the mark. Among other things, this significantly expands the range of action of the level - the measurement range with a receiver is usually several times greater than without it. On the other hand, such equipment inevitably affects the overall cost of the device; and in some models the receiver is not included in the package at all; it must be purchased separately. However, the second option also has its advantages: you do not need to immediately pay for an additional accessory, it can be purchased later, when a real need arises, while some models allow you to choose the optimal receiver model from several options at your discretion.

Note that the receiver can be useful not only for increasing range; These points are described in detail in paragraph “Included parts”.

Accuracy is described as the maximum deviation from the true value of the measured parameter, which the device can give if all the rules for its operation and the corresponding measurements are observed. In both rangefinders and levels, this parameter is usually designated for a certain distance — for example, 3 mm at 30 m; but even for one manufacturer, these "control" distances may be different. Therefore, in our catalog, the accuracy of all devices is recalculated for 1 m distance; with such a record, for the example above, it will be 3/30 \u003d 0.1 mm / m. This makes it easier to compare different models with each other.

It is also worth mentioning that the meaning of the "accuracy" parameter for different types of measuring instruments (see "Type") will be different. For optical levels, it is described in the "SKP" paragraph above. For laser levels of all types, accuracy is the maximum deviation of the mark from the true horizontal (or vertical, if such a function is provided), and for the horizontal, we can talk about both moving the mark up / down and turning it. In rangefinders, this characteristic describes the maximum difference (both in "plus" and "minus") between the readings of the device and the actual distance to the object.

Anyway, the smaller the error, the better; on the other hand, accuracy significantly affects the price of the device. Therefore, it is necessary to choose a specific model for this parameter, taking into account the...specifics of the planned work. For example, for a relatively simple repair in a residential apartment, a high-precision tool is unlikely to be required; and recommendations for more complex tasks can be found in specialized sources, ranging from expert advice to official instructions.

Measuring accuracy provided by a laser distance meter (see "Type")

This parameter is traditionally indicated by the error - the maximum deviation of the obtained results from the actual values, which may occur due to the imperfection of the device. The physical features of laser rangefinders are such that in such devices the error is practically independent of the measured distance. Therefore, the accuracy of such rangefinders is indicated in millimeters. At the same time, in our time, models are generally considered to be high- precision, where this indicator does not exceed 1.5 mm (in some models it is only 1 mm); but even in relatively simple and inexpensive devices, deviations of more than 3 mm are practically not encountered.

The general selection rules for this indicator are traditional: the more accurate the device, the more expensive it is, as a rule. In addition, we emphasize that for everyday and even many professional tasks, the difference described above is not fundamental in accuracy. Therefore, it makes sense to specifically look for a rangefinder with a minimum error in the case when the measurement accuracy “to the millimeter” is fundamental. At the same time, it should be borne in mind that for such measurements, appropriate accuracy in the placement and use of the device itself will be required - otherwise, all the advantages will be nullified by errors from incorrect installation and operation.

Measurement accuracy provided by an ultrasonic distance metre (see "Type").

This parameter is traditionally indicated by the error — the maximum deviation of the obtained results from the actual values, which may occur due to the imperfection of the device. Specifically, in ultrasonic rangefinders, the features of work are such that the actual error directly depends on the measured distance; so it is expressed as a percentage. In fact, converting these figures into actual values is quite easy: just multiply the distance by the percentage accuracy and divide by 100. For example, most of these devices today have an accuracy of 0.5%; if the measurement result showed, say, 7 m, then the largest deviation in this case will be (7 * 0.5) / 100 = 0.035 m, or 35 mm. These numbers are quite significant compared to laser rangefinders; On the other hand, we recall that ultrasonic models are used at short distances (up to 20 m) and mainly in those situations where either the use of a laser device is difficult or high accuracy is not needed in principle.

Regarding specific figures, also note that the lowest accuracy (greatest error) found in modern ultrasonic devices is 1%, and models with an accuracy higher than 0.5% are practically not found. However, taking into account the peculiarities of the application, this difference is usually not fundamental; also it practically does not affect the price.

The maximum deviation from the horizontal position that the device is able to correct "by its own means".

Self-leveling in itself greatly simplifies the installation and initial calibration of levels (see "Type"), which often (and for optical models — mandatory) need to be set horizontally to work. With this function, it is enough to install the device more or less evenly (in many models, special devices are provided for this, such as round levels) — and fine tuning in the longitudinal and transverse planes will be carried out automatically. And the limits of self-leveling are usually indicated for both planes; the higher this indicator, the easier the device is to install, the less demanding it is to the initial placement. In some models, this figure can reach 6 – 8 °.

Approximate time it takes for the self-levelling mechanism to bring the level to a perfectly level position.

For more information on such a mechanism, see Self-Level Limits. And the actual time of its alignment directly depends on the actual deviation of the device from the horizontal. Therefore, in the characteristics, usually, the maximum alignment time is given — that is, for the situation when in the initial position the device is tilted to the maximum angle along both axes, longitudinal and transverse. Since the levels are far from being installed in this position, in fact the speed of bringing to the horizontal is often higher than the claimed one. Nevertheless, it makes sense to evaluate different models precisely according to the figures stated in the characteristics — they allow you to estimate the maximum amount of time that will have to be spent on alignment after the next movement of the device. As for specific indicators, they can vary from 1.5 – 2 s to 30 s.

Theoretically, the shorter the alignment time, the better, especially if there are large volumes of work ahead with frequent movements from place to place. However, in fact, when comparing different models, it is worth considering other points. First, we reiterate that the rate of leveling is highly dependent on the leveling limits; after all, the greater the deviation angles, the more time it usually takes for the mechanism to return the level to the horizontal. So, to directly compare w...ith each other in terms of the speed of self-leveling, it is mainly those devices in which the permissible deviation angles are the same or differ slightly. Secondly, when choosing, it is worth considering the specifics of the proposed work. So, if the device is to be used frequently on very uneven surfaces, then, for example, a model with a leveling time of 20 s and self-levelling limits of 6 ° will be a more reasonable choice than a device with a time of 5 s and limits of 2 °, since in In the second case, a lot of time will be spent on the initial (manual) installation of the device. And for more or less even horizontal planes, on the contrary, a faster device may be the best option.

The speed of rotation of the emitter in a rotating laser level (see "Type"). If the device has several speed options, they are indicated through an oblique line (for example, “0/300/600”), and if the adjustment is carried out smoothly, the entire speed range is given in the characteristics (for example, “0 — 600”).

As the distance from the device to the “target” increases, the length of the path that the laser mark must travel with each revolution also increases. Accordingly, the greater the range of work, the higher the rotation speed should be; otherwise, the line visible to the eye will noticeably flicker, or even completely turn from a line into a rapidly running point. At the same time, an increase in speed increases power consumption and reduces battery life, and also leads to additional wear of the device mechanisms. Therefore, at short distances, a high rotation speed is unnecessary.

In light of all this, manufacturers usually select the maximum rotation speed taking into account the range of the device — so that at such a range the laser effectively forms a mark and at the same time does not rotate too fast. So when choosing a particular model, there is usually no need to pay attention to maximum speed. But what you should look at is the possibilities for choosing the rotation speed. The more such opportunities, the more accurately you can adjust the level to specific working conditions. At the same time, advanced control functions inevitably affe...ct the price, but this impact is often insignificant compared to the total cost of the device itself.

The degree of magnification provided by the lens of an optical level or laser rangefinder (if this function is available, see "Type" for details). Anyway, the greater the degree of magnification, the greater, usually, the range of the device (see above) and the more convenient it is to work with it at a distance. For optical levels, this parameter is also one of the criteria that determine the suitability of the instrument for a particular measurement class; specific requirements for multiplicity, usually, are indicated in specialized instructions.

Note that an increase in magnification, other things being equal, leads to a narrowing of the field of view; To some extent, this can be compensated by increasing the diameter of the lens (also see below), but large lenses significantly increase the overall cost of the level. Therefore, when choosing, it is worth proceeding from the optimal balance between these characteristics.

The diameter of the lens of the optical level (see "Type"). First of all, the aperture ratio, the amount of light transmitted by the optical system, depends on this parameter. The larger the lens diameter, the higher this number and the brighter and clearer the image visible to the operator is, which is especially important in low light conditions (in cloudy weather, at dusk, etc.). In addition, a large lens allows you to increase the angle of the field of view; for more on this, see p. "Magnification".

The root mean square measurement error that occurs during the operation of an optical or digital level.

This indicator is noticeably lower than the deviation indicated in the “Accuracy” paragraph: if the accuracy is indicated in millimeters per meter, then the SKP is in millimeters per kilometer (more precisely, the so-called “double-track kilometer” - a route 500 m long, traveled there and back). There are no contradictions here: the SKP describes exclusively the error caused by the imperfect design of the device itself and arises under absolutely ideal measurement conditions, while the accuracy characterizes the “level-staff” system and describes deviations that are relevant for real conditions. Therefore, SKP as a whole is a formal parameter used to divide levels into accuracy groups - high-precision, precision and technical. The first category includes devices with SCP up to 1 mm/km, the second - up to 3 mm/km, and the third - all less accurate. The minimum accuracy groups required for certain types of work are described in special sources - in particular, regulatory documents and instructions.

The smallest focal length of an optical or digital level (see "Type").

The focal length in this case means the smallest distance to a leveling staff or other object at which the device can clearly focus on it. In most modern levels, this distance does not exceed 1.5 m, and in some models it is about 20 cm at all. So, from a practical point of view, this is more of a reference than a really significant parameter — after all, such devices are used at much greater distances. At the same time, with similar basic characteristics, a shorter focal length, usually, means more advanced and high-quality optics.

The width of the field of view provided by the lens of an optical or digital level (see "Type").

According to the general laws of optics, an increase in the magnification factor leads to a decrease in the angle of view; however, models with the same multiplicity may differ in this indicator. At the same time, on the one hand, the more extensive space the operator sees, the more convenient it is to work with the device, especially in the process of aiming at a leveling staff or other specific target. On the other hand, the difference between specific options is small and in fact it rarely turns out to be fundamental. A typical example: most 24x levels have an angle of view from 1° 20' to 1° 30', which at a distance of 100 m corresponds to a visible space diameter of approximately 2.32 m to 2.61 m. As you can see, the difference in diameters is only about 29 cm, and at shorter working distances it decreases proportionally.

Thus, from this point of view, the viewing angle is more of a reference than a really significant parameter during operation. At the same time, it is worth noting that a wider field of view is often a sign of a more advanced instrument, which, in particular, has a larger lens — and this feature has quite practical advantages (for more details, see "Lens Diameter").

The working range of the compensator installed in the level.

A compensator is a device for smoothing out small deviations of the device installed in the working position. This function is especially important for optical and digital models, in which it is mainly used. Do not confuse it with auto-leveling: the latter is used during the initial installation of the level, and the compensator absorbs small shocks that occur already in the process of work (a typical example is ground vibration from heavy construction equipment nearby). And the range is indicated by the maximum deviation from the horizontal, which such a mechanism can eliminate.

These values in modern levels are small, they are calculated in arc minutes and usually range from 12 – 15' to 30'. At the same time, the wider the range of the compensator, the more efficient it is, the stronger shocks and vibrations it can smooth out; on the other hand, increased efficiency inevitably comes at a price. Also note that compensators can differ in the type of damper (see below).

The type of damper that the level compensator is equipped with.

Let us remind you that compensators are used to protect a device installed horizontally from small shocks and vibrations (for example, on unstable soils or near heavy construction equipment). And the damper represents the “heart” of the compensator - the mechanism directly responsible for alignment; The basis of such a mechanism is a pendulum, which is vertical when the device is stationary and begins to swing when it deviates from the horizontal. To return the level to its working position, you need to stop this pendulum; Different types of dampers differ precisely in the method of braking, the options here can be as follows:

- Magnetic. Braking is carried out due to the field from a permanent magnet. Each time the pendulum passes by such a magnet, the swing slows down until it stops completely.

- Airy. It would be more correct to call this method “weight-based”: to operate the compensator, a massive load is used, attached to the lower part of the pendulum.

By themselves, both described principles have no fundamental differences in either accuracy or efficiency. It is believed that an air damper is better suited for high-precision levels, and a magnetic damper for less precise devices (with so-called technical accuracy); however, in practice everything depends on the overall quality of workmanship of a particular device.

The number of reference points provided in the rangefinder (see “Type”).

The reference point is called “conditional zero” - the point from which the device begins to measure distance. If the device states only one reference point, then this is, as a rule, the rear edge of the case. However, there are few such models on the market, mostly the simplest and most inexpensive rangefinders. Devices with two such points are much more popular - usually the rear and front edges of the case. There are also more advanced options - three or even four reference points. In the first case, the role of an additional conventional zero is played by either a folding stop bracket or a mounting point on a tripod; and the second usually provides both a bracket and a tripod socket.

In any case, a larger number of reference points provides more measurement possibilities, but increases the cost of the device.

The temperature range at which the device is guaranteed to work for a sufficiently long time without failures, breakdowns and exceeding the measurement error specified in the characteristics. Note that we are talking primarily about the temperature of the device case, and it depends not only on the ambient temperature — for example, a tool left in the sun can overheat even in fairly cool weather.

In general, you should pay attention to this parameter when you are looking for a model for working outdoors, in unheated rooms and other places with conditions that are significantly different from indoor ones; in the first case, it makes sense to also make sure that there is dust and water protection (see "Protection class"). On the other hand, even relatively simple and "myopic" levels / rangefinders usually tolerate both heat and cold quite well.

The standard size of the thread used to mount the level/rangefinder on a tripod (if available). This option can be useful if you already have a surveying tripod that you want to use with the tool.

The most popular options in modern devices are 1/4" and 5/8". It is worth noting that 1/4" is a standard size for photographic equipment - accordingly, levels with such a thread can be installed even on ordinary photographic tripods.

The ability to automatically turn off the device after a certain time. This function is found in those types of measuring instruments that require power for operation — first of all, we are talking about laser rangefinders, however, this list may also include levels (see "Type"), both laser and optical with additional digital modules . The main purpose of auto-shutdown is to save electricity: after all, almost all such devices have autonomous power sources (see "Power"), the charge of which is not infinite. Forgetting to turn off the device, you may encounter an unpleasant situation: the batteries are dead, but there are no fresh ones at hand; auto-off prevents these situations and generally increases the operating time without changing batteries or recharging the battery. In addition, this feature is also useful from a safety point of view: automatic laser shutdown reduces the likelihood that its beam will accidentally fall into the eyes of someone around (including a forgetful operator).

In some models, auto-shutdown works on the entire electronics, in others it may be possible to turn off the laser first (as the most energy-intensive and unsafe part), and only after a while — all other electronic circuits.

The time after which the device turns off by itself completely if the user does not perform any action.

See above for more information on auto power off; and his time has a double meaning. On the one hand, if this time is short, then the idle time of the device will be minimal, which helps to save energy. On the other hand, too frequent auto-shutdown (with subsequent switching on for work) is also undesirable — it increases the wear of components and reduces the resource, and it is not always convenient for the user. So manufacturers choose the time, taking into account the balance between these moments, as well as the general class and purpose of the device. So, in some rangefinders, this indicator does not even reach a minute, although in most such devices it is in the range from 3 to 8 minutes; and in some professional devices (primarily levels), the auto-off time can be 30 minutes or more (up to 3 hours).

takes no action.

This parameter is relevant primarily for laser rangefinders. This is due to the fact that in such devices the laser is one of the most “gluttonous” (in terms of power consumption) components, moreover, it is used only directly in the measurement process. Therefore, along with auto-shutdown of the device itself (see above), such devices can also provide auto-shutdown of the laser — mainly as a “safety” function in case the user himself forgets to turn off the emitter. The time of such an auto-shutdown usually does not exceed a minute — one and a half, although there are exceptions.

The wavelength of the radiation emitted by the LED of the level or rangefinder; this parameter determines primarily the colour of the laser beam. The most widespread in modern models are LEDs with a wavelength of about 635 nm — at a relatively low cost, they provide bright red radiation, giving a well-visible projection. There are also green lasers, usually at 532 nm — the marks from them are even better visible, but such LEDs are quite expensive and rarely used. And radiation with a wave longer than 780 nm belongs to the infrared spectrum. Such a laser is invisible to the naked eye and is poorly suited for leveling, but it can be used in rangefinders — of course, with a viewfinder (see "Type" for more details).

The color of the laser beam emitted by the device.

Red lasers are the most popular in our time: they are relatively inexpensive, while they are quite effective and functional, and also quite noticeable on most surfaces. In turn, green lasers are better visible to the human eye (with the same emitter power); however, they are noticeably more expensive than red ones, consume more energy and have a shorter service life, and therefore are much less common.

Blue lines are rarely seen in laser instruments. Their competitive advantage over traditional green and red lasers is their high brightness, which ensures excellent visibility of the beams on many surfaces, incl. when doing outdoor work.

In some devices, you can find two types of lasers at once - both red and green. As a rule, these are levels with several projections, where green is used to build planes, and red is used for point projections.

Class of the laser emitter installed in the device.

The laser power primarily depends on this indicator; and this, in turn, affects the effective range of the device and precautions when working with it. The main options relevant for modern levels and rangefinders are class 2, class 2M and class 3R, here is their more detailed description:

— 2. Such a laser beam is considered safe in case of accidental contact with the eyes, since due to the blinking reflex, the exposure time in such cases usually does not exceed a quarter of a second. This applies to both the naked eye and the use of magnifying instruments such as a monocular or even a telescope. But constant exposure to the eye already poses a danger to vision. The power of such emitters should be below 1 mW. In fact, 2 is the lowest (in terms of power) class used in levels and rangefinders; weaker lasers of classes 1 and 1M simply do not provide the required efficiency. Such emitters are used in the vast majority of low and medium power devices.

- 2M. Such lasers produce a wider beam than class 2 emitters. However, such a beam is also considered safe if it accidentally enters the eye - but only if we are talking about the naked eye. When viewed through a monocular or other magnifying optical instrument, class 2M lasers are dangerous even with low-term (fractions of a second) exposure to the eye. I...n general, this option is quite rare: class 2M is not strictly official and does not have such clear criteria as the original class 2.

- 3R. Also known as IIIa. In fact, it is an analogue of class 2, suggesting a higher emitter power, namely from 1 to 4.99 mW. At the same time, class 3R lasers are generally considered safe in case of accidental contact with the eye when a person reflexively blinks or turns away and the exposure time does not exceed ¼ second. However, such emitters carry a greater risk of serious harm to health than Class 2 devices, so greater caution should still be exercised when using them.

The number of vertical projections issued by the laser level during operation.

Most modern levels are designed for a strictly defined position when working; accordingly, the projection is called vertical, carried out from top to bottom relative to the standard position of the device. If there are several such planes, the level can be used for two or even three walls at once — this is useful, for example, for the simultaneous work of several people. At the same time, there are portable devices that can be used in different positions; for them, the main working plane is called vertical, although during operation it can be located both horizontally and at an angle, depending on specific tasks. Also note that the vertical projection can also give a horizontal line — for example, when installing a level on the floor.

Note that the number of projections is calculated not by geometric planes, but by individual laser elements, each of which is responsible for its own “work area”. For example, if the level has two vertical elements located at opposite ends and directed in different directions, they are considered as two projections even if these projections lie in the same plane.

The sweep angle in the vertical plane provided by the level emitter. If there are several such radiators (for example, on both sides of the case), this parameter is given for each of them separately.

The sweep angle is, in fact, the coverage angle, that is, the width of the sector captured by the emitter when the line is formed. The wider this angle, the more convenient the device is to use, the lower the likelihood that the device will have to be moved up and down to build a line. On the other hand, a larger sweep angle (at the same range) requires more power — and this, accordingly, affects the cost and power consumption.

The number of horizontal projections that a laser level can give out during operation. As in the case of vertical ones (see above), this parameter does not describe the number of geometric planes, but the number of individual work items for projecting horizontal lines. In this case, the projected plane is usually one, and several elements for it may be provided in order to expand the sector covered by the device. For example, a traditional laser level (see "Type") with 4 horizontal projections may be able to cover a full circle of 360 ° — like a rotary (see ibid), but at a significantly lower cost. Of course, there is no need to talk about a full-fledged replacement, because. the power and range of such devices are also not very high; but for work in rooms with distances of several metres, where at the same time wide coverage is important, the usual model with several projections is often preferable to the rotational one. Rotary levels themselves, by definition, have one horizontal projection.

The sweep angle in the horizontal plane provided by the level emitter. If there are several emitters, their total coverage angle is indicated here; a typical example of such devices are models for full 360 °, not related to rotation.

Actually, all rotary devices, by definition, provide a coverage of 360 °. Therefore, it is worth paying attention to this parameter in cases where we are talking about more traditional laser levels. And here it is worth considering that a larger coverage angle, on the one hand, can provide additional convenience, on the other hand, it increases the price and power consumption of the device. So when choosing, you should proceed from real needs; detailed recommendations on this subject can be found in special sources.

The number of individual points projected by the laser tool — rangefinder or level, see "Type" — when working. In the first case, one point projection is standardly provided — more is simply not required to measure distances. In levels, there can be several points, and some models do not have planar projections at all and work only with points. This format may not be as convenient as displaying lines; at the same time, with the same laser power, dot marks shine brighter and are more visible, especially at long distances. In addition, there are certain types of work for which point projection is considered optimal — for example, laying sewers, determining the locations for two holes in opposite walls, etc.

Zenith in this case is called a point projection directed vertically upwards.

By itself, such a projection can be useful, for example, if you need to make holes in several floors, located strictly one above the other. It is enough to point the "anti-aircraft" laser at the hole located directly above it — and the mark from the beam that passed through this hole will indicate the point for the hole on the next floor. And if the device also has the nadir function (see below), then the combination of these functions will be very convenient for marking the floor and ceiling at the same time — for racks, partitions, etc.: marks from the zenith and nadir are located strictly one above the other.

Nadir in this case is called a point projection directed vertically down.

By itself, such a projection can be used, in particular, for making holes on the same vertical in ceilings located at different levels. It is enough to make one of the holes, install a level above it — and the laser beam going vertically downwards will indicate the location of the next hole. And in devices that also have the zenith function (see above), the marks from the zenith and nadir projections are located strictly one above the other. This is very convenient when marking the floor and ceiling at the same time for racks, partitions, etc.

The ability to change the operating mode of the laser level by changing the position of the prism that scatters the laser beam. To be more precise, this function allows you to switch the same emitter to different modes: vertical, horizontal, cross-shaped, dot. The specific set of these modes may be different, depending on the model, but anyway, it should be borne in mind: manual prism adjustment is very poorly combined with high-precision mechanisms. Therefore, this function can be found only in the simplest models, designed exclusively for simple everyday tasks and not providing for special accuracy.

Ability to disable the compensator installed in the level. To be more precise, we are talking about the ability to disable the self-leveling system (recall, it is used to automatically bring the device to the horizontal during initial installation).

Blocking the compensator can be useful in two cases. The first is transportation: compensators are rather delicate mechanisms, and when switched on, they do not withstand the shocks and shocks that the device can be subjected to when moving from place to place. The second case is the installation of the device at an angle, when bringing it to the horizontal is simply superfluous.

A design feature found in rangefinders — mainly laser ones.

The position bracket is a special stop on the body of the device, designed for convenience when measuring distances in some situations. This stop is one of the reference points — that is, by setting the appropriate settings, you can measure the distance not from the front or rear edge of the case, but from the bracket. This is useful, in particular, when measuring the distance from various edges — door and window openings, the edges of countertops and borders, etc.: in such situations, it can be convenient to rest the bracket on the starting point of measurement.

Own screen on the device body.

All displays are used to display various additional information, which makes control more convenient and clear compared to models without displays ; but the specific functionality and features of the screen may vary, depending on the type. There are black and white options, backlit displays, color and even touch screens. More details about each:

— B/W without backlight. The simplest and most inexpensive type of display: a black-and-white LCD sensor without its own backlight. Despite their overall simplicity, such screens can have quite extensive capabilities: technically, they can display data related to the operation of the device (for example, the results of rangefinder measurements), and other additional information, including quite specific ones. In fact, the only thing that b/w displays are not suitable for is displaying images from a digital camera. In practice, the functionality of the display is selected according to the capabilities of a particular device. As for the lack of backlighting, this feature makes it difficult to use in low light conditions, but it reduces the price and power consumption. In addition, under the sun or other bright lighting on advanced backlit screens the image may “fade”, while on the simplest black and white screens wi...thout backlight it, on the contrary, becomes even clearer.

— B/W with backlight. Black and white screens equipped with backlight systems. Note that this category actually includes two types of displays: traditional black-and-white LCD matrices in the “black image on a white background” format, supplemented by an external lighting system, as well as single-color screens in the “light image on a black background” format, where the light itself can glow. image. Be that as it may, such displays can be used without restrictions in low light, but the downside of this is increased power consumption - especially in models where the backlight is constantly on.

- Colored. The functionality of color displays can be different - from the simplest LCD screens, capable of displaying only a few primary colors (for example, highlighting the most important numbers on the screen in a different color), to full-color matrices (like tech used, for example, in laptops). The first type is somewhat more convenient and clearer than the b/w displays described above, costs a little more, but has no other differences. The most advanced color screens, in turn, can even display a picture from a digital camera - and, in fact, they are mainly used in devices equipped with such cameras.

- Touch. The most advanced type of display. Such screens are almost always made in color and equipped with backlighting, and touch controls also allow them to be used to control the device (similar to what happens in smartphones and tablets). In terms of control, touch screens are more convenient and intuitive than traditional panels with buttons, switches, etc.; they are much better suited to handle the abundance of functions, and also provide some additional capabilities that are not available with traditional controls. On the other hand, such equipment is not cheap, and it simply does not make sense to use it in relatively simple and inexpensive devices - for such models, more affordable displays, even the simplest black and white ones, are quite sufficient. Therefore, the presence of a touch screen is almost guaranteed to be a sign of a high-end device with an abundance of functions.

Digital camera built right into the body of the device.

Note that such equipment, by definition, is provided in digital levels, so for such devices the presence of a camera is not specifically specified. And most of the devices for which this feature is indicated relate to laser rangefinders: the image from the camera is displayed directly on the screen, and the entire system is used as a viewfinder to aim the beam at the desired object. The built-in camera is especially useful at considerable distances (from 50 m or more), at which it is difficult to see the laser mark and control its position. Actually, powerful “long-range” rangefinders are equipped with cameras - in simpler devices, there is no need to use such equipment, especially since it significantly affects the price.

Traditional mechanical tape measure, built right into the body of the device.

This function is most popular among laser rangefinders: a tape measure is also intended for measuring distances, its use allows you to save battery power, and in some cases a flexible metal tape is even more convenient than a laser. Note that such devices usually do not look like rangefinders with additional equipment, but rather like traditional tape measures, supplemented by a laser.

Also, such equipment can be found in separate laser levels — mostly simple and inexpensive models designed for purely domestic use.

Level based on a bubble capsule (or several such capsules) built into the body of the instrument.

Such a device allows you to control the position of the device — namely, to check whether it is set horizontally; however, some models also provide levels for the vertical position, and sometimes even for tilting at 45 ° or another angle. But the specific purpose of the bubble level may be different, depending on the type and general level of the device. The most popular option is a preliminary, rough installation of the laser level in the horizontal: the initial adjustment is carried out manually using a level, and after that the built-in self-leveling mechanism is activated. In simple and inexpensive household levels where high accuracy is not required, the bubble chamber may even be the only way to set it to the desired position; and some of these devices can also be used as full-fledged building levels.

A built-in detector that allows you to use the device to search for metal parts or wires invisible to the eye — for example, fittings or electrical cables hidden in the wall.

Note that the functionality of such a detector should be specified separately: if live wiring can be detected by almost all devices with this function, then the ability to search for metal objects is not always available. It is also worth noting that in fact such equipment is not required so often, but is expensive. Therefore, only a few models have the ability to detect metal / wiring nowadays (although there are levels and rangefinders among them).

The presence of a Bluetooth module allows you to broadcast the measurements to the connected device. Thus, you can make the device as compact as possible, and read the received data directly from the phone. And in the era of high technology and the ability to control the phone with any device, such a decision looks quite reasonable.

Wireless technology. Technically, it is more advanced than Bluetooth: it can be used both for direct communication between devices and for connecting to computer networks (including the Internet), and the communication range even in the simplest standards reaches 100 m. At the same time, in levels and rangefinders Wi -Fi is used extremely rarely — literally in single models. The specific possibilities of such communication, again, should be specified separately: theoretically, they can vary from direct connection with a laptop, tablet, etc. to remote access and control via the Internet, but in fact, the functionality is selected according to the specialization and general level of a particular device.

It's a COM port. Service connector for data exchange with a computer or laptop, as well as some specialized equipment. It is found in certain models of laser rangefinders and digital levels; through the COM port, you can transfer measurement data, manage settings, and in the second case, even broadcast an image from the level's camera.

Note that in its pure form, RS-232 connectors are extremely rare in modern computers — however, there are adapters from this interface to traditional USB.

The functions of the rangefinder allow you to more comfortably perform work and not calculate various mathematical formulas, but with one button to get the result after the measurements have been taken. Among such assistants there are area / volume measurement, indirect measurements (Pythagorean theorem), tilt angle measurements, height measurement, trapezoid measurement, addition / subtraction, min. / maximum values, continuous measurement (tracking), countdown timer, layout mode, painter mode, memory of the last measurements and others. More about them:

— Measurement of area/volume. Built-in software tool for measuring the area and / or volume of premises or large objects. This function works as follows: the user only needs to measure the length, width, and for volume, also the height of the object, after which the rangefinder will independently multiply the received data and display the final result.

— Indirect measurements (Pythagorean theorem). A function that allows you to determine the length of one of the sides of a right triangle from its othe...r two sides. One of its most popular uses is to measure the height of buildings, walls, poles, and other objects without having to approach them. To do this, you need to place the rangefinder at ground level and measure two distances from this point: to the foot of the object, horizontally (one of the legs) and to the top of the object (hypotenuse). Based on the Pythagorean theorem, the device will automatically calculate the length of the second leg - that is, in this case, the measured height.

— Measuring the angle of inclination. A feature that turns the rangefinder into an advanced level. When it is turned on, it is enough to attach the device with its side to an inclined surface or other similar object - and the built-in sensor will automatically determine the angle of inclination, displaying it on the display.

- Height measurement. A special mode for measuring the height of various objects. Note that in many devices this function is actually performed by indirect measurements according to the Pythagorean theorem (see above). Therefore, the possibility of measuring height is indicated mainly in tech models that have more advanced capabilities for such measurements. A typical example is an extended version of the Pythagorean theorem, which is used when a rangefinder is mounted on a tripod at a certain height from the ground. With this placement, to measure the height, you need to take three measurements: the distance to the foot of the object (the rangefinder will be tilted down), to the object horizontally and to its top. According to the data received, the device will build two triangles, perform the necessary calculations and give the final height value.

- Measuring the trapezoid. A function that allows you to determine the length of the fourth side and the total area of the figure from three sides of a rectangular trapezoid. It is mainly used to calculate the area of walls and facades in houses with sloped, gable and other similar roofs. If the upper part of the wall has a slope to one side, to determine the area, it is enough to measure the length of the base and the height of the two sides adjacent to the edges of the roof. If the upper part of the wall adjoins a gable roof, the wall must be divided into two trapeziums and measured using the same procedure; a similar method can be used with roofs of more complex shape, due to which the upper side of the wall looks like a broken line.

- Addition / subtraction. Possibility to sum the results of measurements, as well as to subtract one result from another. One of the simplest computing functions - which, nevertheless, can make life much easier for the user.

— Min. / maximum values. In this mode, the device takes a whole series of measurements at a short interval, and then displays the smallest or largest of the obtained values. As a rule, modern rangefinders provide for both formats of operation (both minimum and maximum), which is why they are combined into one function. However, the meaning of these options is different. So, the maximum value allows, among other things, to accurately determine the size of the room: it is enough to place the device in the corner, turn on the appropriate mode and slowly draw the laser horizontally in the region of the opposite corner; the largest distance obtained will be the length of the size. In turn, the minimum value can be useful, for example, to measure the length of the perpendicular to the wall; the measurement technique here is similar, and the smallest number obtained will just correspond to the length of the perpendicular.

— Continuous measurement (tracking). In this mode, the device continuously takes measurements at a sufficiently high frequency (usually 1 - 2 times per second), displaying the corresponding results on the display. This format of work is also called "roulette mode", it allows you to constantly track the distance from the rangefinder to a specific object. This can be useful, for example, if you need to accurately measure the distance from a wall, pole or other landmark: instead of taking several measurements, trying to “get” the device into the right position, just turn on tracking and move the rangefinder until the desired distance value is not displayed.

- Countdown timer. A function that allows you to automatically take measurements after a specified period of time. A kind of analogue of shooting on a timer in cameras: just point the device at the desired point, turn on the countdown - and at the end of it the device will work itself. The countdown is mainly used to eliminate the twitching of the body, which inevitably occurs when measuring manually (at the touch of a button); this is especially useful for high precision measurements and/or when using the instrument from a tripod or other stand.

- Markup mode. A mode that allows you to divide a particular segment into sections of a certain length - for example, under posts for a fence. The specific implementation and capabilities of this mode may be different, these nuances should be clarified in the instructions for a particular device. So, in some devices, you can measure the total length of the segment, set the number of identical sections - and the electronics will calculate the length of each part. In others, you can manually enter the length of the segment, or even several options for their length at once (for example, the distance from the starting point to the first mark and further gaps between marks). In any case, in the marking mode, the rangefinder works in the same way as the tracking described above - constantly taking measurements and displaying the current result on the display. And when measuring, the device must be smoothly moved along the marked line; when the next mark is reached, a signal will be given.

- Painter mode. A mode designed to calculate the total area of walls (internal in the room or external in the entire building). Such an opportunity is especially convenient for painting work (hence the name), as well as other similar tasks - wallpapering, laying tiles, external insulation, etc. The “painter mode” is implemented, as a rule, as follows: using the device, the master first measures the total perimeter of the walls, then their height (or vice versa), after which the electronics automatically calculates and gives the final value.

— Memory of the last measurements. The ability to save the results of the last few measurements in the memory of the device. In most models with this function, the memory of the last measurements is included initially, the user does not need to specifically change any settings. The convenience of such a memory is obvious: it allows, if necessary, to return to previous results and clarify a particular value without repeating the measurement. It is only necessary to bear in mind two points. Firstly, the number of memory cells can be different - as a rule, it is in the range from 20 to 100 and is indicated here, right under the words "memory of the last measurements." Secondly, when these cells overflow, the newest results are automatically overwritten in place of the oldest ones; and such a function as protecting individual cells from overwriting is usually not found in laser rangefinders (although exceptions are possible - this point should be clarified in the documentation for a particular device).

- Calculator. A traditional calculator that allows you to perform various calculations at the request of the user. These can be both operations with data obtained during measurements, and operations with numbers entered manually.

— Horizontal mode Smart. "Smart" mode, which allows you to measure and calculate a whole range of dimensions and angles, literally on the spot. A typical example of the implementation of Smart looks like this: a rangefinder from the same point measures two distances to a wall or other similar object - one is the smallest (along the perpendicular), and the second to a certain point “nearby”. After that, based on the received data, the device calculates the angle of rotation and the distance between the points. Other, more specific functions are also possible.

— Measurement of inclined objects. Various additional functions related to the measurement of inclined objects (in addition to determining the angle of inclination described above). The specific set of such capabilities may vary; they should be specified separately.

We also note that in modern rangefinders there may be other possibilities, in addition to tech listed above.

The level of protection against harmful influences (in the first place — the penetration of foreign objects) that the body of the level / rangefinder provides in accordance with the IP standard. This standard describes two separate characteristics — protection against solid objects and against water. They are designated respectively by the first and second digit after the IP index; the higher the number, the higher the degree of protection.

Considering that levels and rangefinders usually have to work on construction sites where there is a lot of dust, the minimum level of protection against solid objects for such tools is the fifth. It allows some dust to get inside, but in such a way that it does not affect the performance of the device. The maximum level of dust resistance is 6, which implies complete protection from solid particles.

The second characteristic, protection against moisture, in levels and rangefinders is usually indicated starting from level 4. Officially, it provides protection "against spray from any direction", in fact this means that it can be used in moderate rain with strong winds — a useful point in that if the tool is to be used outdoors. Level 5 allows operation during storms and downpours, a device of the sixth class can withstand being hit by a wave, the seventh — a short-term immersion under water up to 1 m, and the eighth — even a long stay under water. However, for a conventional construction tool, too high water resistance i...s usually not required.

Actually, the most popular option in modern construction tools is the IP54 class: it is quite enough even for work in bad weather, while such cases are relatively inexpensive. There are also more protected models, but less often.

It is also worth noting that a certain level of dust and water protection in itself is usually provided even in devices that do not have an IP marking. The absence of this index does not necessarily mean the absence of protection — it only says that the case has not been officially certified according to the IP standard. But if you need an additional guarantee of reliability, you should still pay attention to certified options.

The type and number of batteries used in the level/distance meter. All elements of standard sizes (AA, AAA, C, D, PP3) are available in two formats — disposable batteries and rechargeable batteries. This gives the user a choice: either buy relatively inexpensive batteries every time, or invest once in a rechargeable battery with a charger, and then simply charge the battery as needed. Branded batteries are, by definition, made only rechargeable, as are 18650 batteries.

Specific types of power today can be as follows:
— AA. A standard battery, known as a "finger battery". The power of these batteries is average, they can be used both in simple and quite advanced devices. This power supply is convenient due to the fact that AA batteries are very widespread and sold almost everywhere — due to this, finding and replacing them is usually not a problem.
— AAA. A smaller version of the AA element described above — almost identical in shape, but thinner and shorter. Such elements, known as "mini-finger" or "little fingers", have a rather low capacity and power, but are useful for portable devices, where compactness is crucial. They are also quite widespread.
— C. A cylindrical element, in the form of a rather thick "bar...rel" — with a length of 50 mm, the diameter is 26 mm. Due to its higher capacity and power than AA, it is better suited for advanced models with "long-range" lasers, but is less commonly used and generally less common.
— D. The largest and most capacious type of standard batteries found in modern levels and distance meter: thickness and diameter are 62 and 34 mm, respectively. The main area of application for D batteries is powerful professional devices.
— Rechargeable battery. In this case, the tool is powered by an branded battery that does not belong to any standard size. This option is good because such batteries are initially created for a specific model of the level/distance meter and are supplied in the set (and in some models they are made non-removable); in addition, their specifications can significantly exceed those of standard elements of a similar size and weight. On the other hand, such power source is less convenient when the charge runs out at the wrong moment: the only way to remedy the situation is usually to recharge, and it takes quite a long time (whereas standard batteries can be replaced in just a minute).
– 18650. The name of these batteries comes from their dimensions: 18.6x65.2 mm, cylindrical, outwardly they resemble somewhat enlarged AA batteries, but they have an operating voltage of about 3.7 V and a higher capacity. In addition, all 18650 type batteries are by definition not disposable, but rechargeable batteries (lithium-ion type).

— PP3. 9-volt batteries of a spesific rectangular shape, with a pair of contacts on one of the ends. Due to the high operating voltage, they provide high power and actual capacity, so one such battery is usually enough for operation.

— LR44. Miniature batteries of "coin" type, 11.6 mm in diameter and 5.4 mm thick. Usually installed in sets of 3 and are used in compact low-power laser levels, for which small size is more important than power and capacity. Note that specifically the LR44 marking refers to relatively inexpensive alkaline batteries; more expensive and advanced silver-zinc power supplies are referred to as SR44, or 357.

— 23A12V. A rather rare option: cylindrical batteries (length 29 mm, diameter 10 mm) with a nominal voltage of 12 V.

The ability to power the device from a household electrical outlet, in other words, a regular outlet.

Modern levels and rangefinders are powered by batteries or accumulators by default. With all its advantages (first of all, freedom of movement and independence from sockets), this power supply method also has serious disadvantages: limited operating time, as well as the need to buy additional batteries or look for a power source to charge the battery (and the charging procedure also takes quite a long time). ). Thus, some modern appliances additionally provide the possibility of connecting to a power outlet and operating from the mains. This primarily allows you to save battery power; and many models are also capable of recharging batteries (built-in or even removable) in the process.

Note that the ability to work from the network is found mainly among traditional laser levels, and at different levels — from compact household models to fairly powerful professional equipment.

Connector type for synchronization with a smartphone and a computer or for charging the battery of the device.

Many modern levels and rangefinders are equipped with USB ports. The type of this interface is specified in this paragraph, but the options can be as follows:

- microUSB. Quite old, but still a very popular connector for portable gadgets. Slightly smaller than USB-C, it has an asymmetrical shape and a one-sided design.

- USB-C. The newest type of miniature USB connectors. Ports of this type are convenient primarily due to the symmetrical design, which allows you to insert the plug in either direction (unlike earlier standards, including microUSB). In addition, through USB-C, it is easier to implement many advanced features, in particular, fast charging technologies; however, it all depends on the specific model of the device.

We also note that both types of connectors are universal standards, a huge number of chargers, cables and adapters are produced for them. The presence of a USB port provides very extensive opportunities for synchronizing the level and rangefinder with a computer or mobile gadgets. As a rule, to use the possibilities of such a connection, you need to install special software from the manufacturer's website. Specific connectivity options may vary. In particular, it is not uncommon to find the function of downloading data from saved measurements to a PC.

A...t the same time, USB is used to charge the battery in the level / range finder: for this purpose, you can use an adapter for an outlet or car cigarette lighter, a portable power bank, a USB connector of a computer or laptop, the same port in an extension cord or even a wall outlet, etc. It comes to the point that some devices with a USB interface are completely supplied without a charger, with only one cable: it is assumed that it is not difficult to find a power connector for such a cable in our time.

Operating time of the device on one battery charge.

It is worth considering that these figures are quite approximate, since the operating time is measured under certain standard conditions (usually continuous operation at nominal power). And since in practice conditions may differ markedly, the operating time may turn out to be noticeably shorter or longer than stated. In addition, if the device uses replaceable batteries (AAA, AA and the like), then autonomy will also depend on the quality of the specific batteries/accumulators. Nevertheless, based on the data specified in the characteristics, it is quite possible to evaluate the capabilities of specific models and compare them with each other: the difference in the declared operating time, as a rule, proportionally corresponds to the difference in practical autonomy under the same conditions.

We also note that the operating time is specified mainly for levels; in rangefinders another parameter is more often used - the number of measurements (see below).

A parameter that characterizes the performance of the device on a single battery charge. Shows how many measurements can be taken without recharging.

The name of the battery platform supported by the device. A single battery platform is used to combine various power tools of the same brand into one line (screwdriver, grinder, circular saw, etc.). Devices on the same platform use interchangeable batteries and chargers. Thanks to this, for example, there is no need to select a battery for each individual model of a power tool, because one purchased as a spare battery can be used in various power tools, depending on the situation or as needed. Batteries of the same platform basically differ from each other except perhaps in capacity.

The model of a standard battery allows you to find out its characteristics in more detail, and also helps you understand what devices it is like and which one should be purchased in case of a replacement due to a malfunction or, if necessary, buy another similar one.

Battery models that the corresponding type of electric planer is compatible with (see "Power Source"). This information will be useful in cases where the battery(ies) must be purchased separately, for example, if the tool does not come with a battery at all, if you need to supplement the original package, or if the existing battery has failed.

— holder. Devices for fixing the level / range finder on various surfaces. Such a device differs from a tripod primarily in its small size — within a couple of tens of centimeters. On the other hand, most holders allow you to install the device not only on horizontal, but also on vertical surfaces — for example, walls (and some are exclusively wall-mounted). Anyway, this function greatly expands the installation possibilities.

— Receiver. laser radiation supplied with the device. This device is usually equipped with laser levels, less often with rangefinders, and it is not required at all for optical instruments. The main purpose of the receiver is situations where the laser mark is not visible to the naked eye — for example, at a long distance or in bright light. More details on the features of its application are described above in the paragraph “Measurement range (with receiver)”.

— Tripod. Most modern instruments have a standard size thread and can be used with any suitable tripod. On the other hand, a complete tripod is most often specially designed for a certain model and optimally matches it in terms of general characteristics. In addition, this configuration option relieves you of the need to look for and purchase a suitable tripod yourself.

— Case / case. The main function of these devices is to protect...the device from bumps, scratches, dirt, temperature changes and other adverse effects; for this, of course, improvised means can also be used, but specialized protection is usually both more convenient and more reliable. In addition, almost all cases and most covers greatly simplify the transportation of the tool — in particular, due to the fact that they can also be used for complete accessories.

— Remote control. Among rangefinders and optical levels, this function is practically not found, because. working with them involves the constant stay of the device in the hands of the operator. But for laser levels that require you to regularly move from the device to the surface to be marked and back, the remote control can be a very useful addition — due to the fact that it minimizes such movements. For example, after marking the "front of work" on the wall according to the projection from the level, you do not have to approach the device to turn it off — just give a command from the remote control. At short distances, the savings in time and effort may not be so obvious, but over large areas, they can become quite noticeable.