Measurement accuracy (V⁻)
Measurement accuracy provided by the instrument.
Measurement accuracy for multimeters is usually indicated by the smallest error (in percent) that the device is able to provide when measuring direct current. The smaller the number in this paragraph, the higher the accuracy, respectively. At the same time, we emphasize that it is the smallest error (the highest accuracy) that is usually achieved only in a certain measurement range; in other ranges, the accuracy may be lower. For example, if in the range "1 — 10 V" the device gives a maximum deviation of 0.5%, and in the range "10 — 50 V" — 1%, then 0.5% will be indicated in the characteristics. Nevertheless, according to this indicator, it is quite possible to evaluate and compare modern multimeters. So, a device with a lower claimed error, usually, and in general will be more accurate than a model with a similar performance with a larger error.
Data on measurement accuracy in other ranges and modes can be given in the detailed characteristics of the device. However, in fact, this information is required not so often — only for certain specific tasks, where it is fundamentally necessary to know the possible error.
AC minimum
The upper limit of the lower sub-range in which the device can measure alternating current (see "Type of current").
The operating ranges of modern multimeters and other measuring instruments are usually divided into subranges. This is done for accuracy and convenience in measurements: the lower the subrange, the smaller values it covers, the higher the measurement accuracy at low current values. The minimum alternating current describes exactly the lower range, designed for the weakest current values: for example, if the characteristics in this paragraph indicate 500 μA, this means that the lower subrange allows you to measure currents from 0 to 500 μA.
It is worth choosing according to this indicator taking into account the specifics of the planned application: for example, a device with low rates can be useful for delicate work, such as repairing computers or mobile phones, but especially high current sensitivity is not required for servicing household electrical networks.
In box
Items included in the scope of supply other than the instrument itself.
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Battery. The power supply is necessary for the operation of the circuits of a digital device (see "Type"), and in analogue it is used for all measurements, except for voltage and current measurements. A battery as such a source is most often the most convenient (for more details, see "Power"); its presence in the kit eliminates the need to purchase a battery separately. At the same time, we note that the term "battery" in this case is very conditional — it can mean both a rechargeable element and a simple disposable battery. This point does not hurt to clarify before buying.
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Measuring probes. Styli are the basic tool needed for most measurements; in fact, the only type of instrument that can do without probes is
oscilloscopes(see "Device"). The presence of probes in the kit is convenient, first of all, because such accessories are optimally suited for a specific device — an important point, given that modern multimeters can vary in design and size of the sockets for the probes.
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Data cable. Cable for connecting the device to a computer. The most popular connectors found in such cables are RS-232 (COM port) and USB, the specific option in each case should be specified separately. However, anyway, connecting to a computer provides many add
...itional features — for example, automatic saving of measurement results or even comparison of measured parameters with reference ones; specific functionality depends on the model of the device and the software used.
— Case/case. Case for storing and carrying the device. Cases are usually called cases made of hard materials, cases are made of soft ones. Anyway, the case provides not only protection from dust, moisture, shock, etc., but also additional convenience — usually, it provides space not only for the device, but also for accessories for it (the same probes). At the same time, each type of case has its own advantages: the cases are durable and well protect the device from shocks, the cases are more compact both during use and during non-working hours. Of course, impromptu packaging can also be used for storage and transportation, but the complete case is at least more convenient, if not more reliable.Display backlight
The presence
of a backlight in the display of the device.
This function allows you to read the display regardless of lighting conditions — at dusk and even in total darkness. If there is not enough external light, just turn on the backlight, and the readings will be perfectly visible.
