Comparison Bosch GLM 30 Professional 0601072500 vs Bosch PLR 25 0603016220

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.

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.

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.

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 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.

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).