Comparison BAKKU BA-2202 vs ANENG SZ02

The upper limit of the lower sub-range in which the device can measure DC voltage (see "Type of voltage").

The operating ranges of modern multimeters and other measuring instruments are usually divided into subranges. This is done for accuracy and convenience when measuring: for example, to assess the quality of AA batteries, you can set the subrange “up to 3 V” — this will give an accuracy of up to tenths, or even hundredths of a volt, unattainable when measuring with a higher threshold. The minimum constant voltage describes exactly the lower subrange, designed to measure the smallest voltage values: for example, if 2000 mV is indicated in this paragraph, this means that the lower subrange covers values \u200b\u200bup to 2000 mV (i.e. up to 2 V).

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 for servicing the on-board electrical network of a car, especially high voltage sensitivity is not required.

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.

The upper limit of the lower sub-range in which the device can measure AC voltage (see "Type of voltage").

The operating ranges of modern multimeters and other measuring instruments are usually divided into subranges. This is done for accuracy and convenience in measurements: for example, to test a transformer that should output 6 V, it makes sense to set a subrange with an upper threshold of 10 V. This will ensure accuracy up to tenths of a volt, unattainable when measuring with a higher threshold. The minimum constant voltage describes exactly the lower subrange, designed to measure the smallest voltage values: for example, if 2000 mV is indicated in this paragraph, this means that the lower subrange covers values \u200b\u200bup to 2000 mV (i.e. up to 2 V).

If the device is purchased for measurements in stationary networks — household at 230 V or industrial at 400 V — you can ignore this parameter: usually, the minimum subranges are not used. But to work with power supplies, step-down transformers and various “thin” electronics served by low voltage alternating current, it makes sense to choose a model with a lower minimum voltage. This is connected not only with the measurement range: a low threshold, usually, indicates a good measurement accuracy at low voltages in general.

The largest alternating voltage (see “Type of voltage”) that can be effectively measured using this model. This parameter is important not only for measurements as such, but also for safe handling of the device: measuring too high voltage will, at best, trigger emergency protection (and it is possible that after that you will have to look for a new fuse to replace the burned one), at worst — to equipment failure or even fire. In addition, for safe measurements, a voltage margin is highly desirable — this is due both to the characteristics of the alternating current and to the possibility of various emergency situations in the network, primarily voltage surges. For example, for 230 V networks, it is desirable to have a device for at least 250 V, and preferably 300 – 310 V; detailed recommendations for other cases can be found in special sources.

Note that most multimeters and other similar devices have several measurement ranges, with different maximum thresholds. So, for a safe measurement of voltage close to the maximum, you need to set the appropriate mode in the settings.

The upper limit of the lower sub-range in which the device can measure resistance.

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 the values it covers, the higher the accuracy of measurements at low resistance values. The minimum resistance describes exactly the lower range, designed for the weakest current values: for example, if the characteristics in this paragraph indicate 500 Ohms, this means that the lower subrange allows you to measure resistance from 0 to 500 Ohms.

When choosing for this indicator, you need to consider how important it is for you to accurately measure small resistances. At the same time, we note that the 500 Ohms given in the example are a fairly good indicator, indicating a fairly solid resistance measurement accuracy; in relatively inexpensive multimeters, this indicator can be 2.5 or even 10 kΩ, which ensures accuracy at best up to several tens of ohms.

The diagonal of the display used in the instrument.

Digital models are equipped with displays (see "Type"), and for an oscilloscope, this item of equipment is mandatory regardless of type. Actually, the diagonal of the display is important primarily for oscilloscopes and scopmeters (see "Device"): the larger the display, the more accurate and convenient for perception the signal graph displayed on it and other parameters. On the other hand, a screen that is too large will cost a lot, and will also significantly affect the overall dimensions of the entire device. Therefore, the best compromise for such devices is considered to be a diagonal of 5 – 6 "— it allows you to get quite clear data and at the same time does not lead to a significant increase in the price and dimensions of the device.

For classic multimeters, the display size is not so critical, besides, manufacturers try to select the screen in such a way that it is not too large and at the same time convenient enough to read the readings. Therefore, in such cases, the screen size may not be indicated at all.

- Checking the transistor. The ability to use the device to test transistors, more precisely, the presence of an appropriate mode in the design of the device. Technically, the performance of a transistor can be checked to a certain extent with an ordinary ohmmeter, for this there is an appropriate technique. Nevertheless, it is much easier to use a special mode - just connect the transistor to the multimeter in an appropriate way, and the device will automatically give data on the health or malfunction of the part (and sometimes additional characteristics for it). Most often, for such measurements, there is a special block on the case with a set of sockets for transistor outputs (with separate sets of sockets for pnp and npn types).

- Checking the diode. The presence of a special diode test mode in the design of the multimeter. The principle of a diode is to allow electric power to flow in only one direction; therefore, the serviceability of such a part itself can be determined without a special mode, for example, in the mode of a conventional ohmmeter, “continuity” of the circuit (see below), or in some other ways. However, special mode is often more convenient - both due to the simplicity of the procedure itself, and due to the fact that many devices in this mode are also able to measure the forward voltage drop across the diode (the lowest voltage required to pass power in the forward direction...).

— "Continuity" of the chain. Possibility of operation of the device in the "continuity" mode of the circuit - checking the presence of contact between two selected points. This mode differs from the usual check with an ohmmeter in that the presence of a contact is accompanied by an audible signal (hence the name). Such a signal saves the user from having to look at the scale of the device every time to clarify the presence or absence of contact, and this greatly speeds up the work and can be very useful if you need to “ring out” many sections at once.

- Meander generator. Ability to operate the device in the meander generation mode - a signal with a rectangular pulse shape and a duty cycle (see above) at level 2. The graph of such a signal looks like a set of rectangular peaks and dips of the same length. Meander is a regular signal format for modern digital technology; a signal of this type, generated by a multimeter, is used to test microcircuits, logic elements, amplifiers and other similar elements and circuits (for performance, signal flow, etc.).

— Non-contact detection (NCV). Ability to detect live parts without direct contact with them. This method of detection is as safe as possible, besides, it allows you to find elements hidden from the eye: for example, using a device with this function, you can detect wiring in walls and determine places where you can drill without fear of damaging the wire.

— True RMS. Ability to measure with the True RMS device - the true RMS value of the strength of the alternating power (see "Type of power"). The strength of the alternating power is determined not by the actual value (it will be different at each moment of time), and not by the maximum amplitude (after all, the maximum values also occur only at certain points in time), but by the root mean square. At the same time, in devices that do not support True RMS, this value is displayed as follows: the alternating power is rectified, its value is determined and multiplied by a factor of 1.1 (this is due to the mathematical features of the measurements). However, this method is only suitable for an ideal sinusoid; with a distorted signal, it gives a noticeable, and often even unacceptably high error. Distortions are found in almost any AC network, which can lead to serious measurement errors and subsequent problems (for example, to the selection of too “weak” automatic fuse). True RMS technology takes into account all these features: devices bearing this marking are able to accurately measure AC RMS power, regardless of how its shape corresponds to a perfect sine wave.

- Auto-selection of the measuring range. A function that allows the device to automatically select the optimal measurement range - so that the result is displayed on the screen as accurately as possible. This function is found only in digital instruments (see "Type"). Note that when using it, the user will still have to set certain basic settings - for example, “direct power, power, milliamps” or “alternating power, voltage, volts”. However, the device will perform a more precise setting itself: for example, to measure voltage in hundreds of volts, the range 0 - 1000 V can be used with an accuracy of 5 V, and when a 1.5 V battery is connected, the device will automatically switch to the range 0 - 12 V and display the result is already accurate to tenths of a volt. At the same time, the design may also provide for a completely manual measurement mode, with a range selection at the request of the user, however, the presence of such a mode will not hurt to clarify separately.

- Auto power off. The function of automatically switching off the Meter after a period of inactivity helps to conserve the charge of the used batteries.

Items included in the scope of supply other than the instrument itself.

— 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.

— 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.

— 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.