It is also known from the general school physics course that an electrical circuit is characterized by a number of parameters. Among them, the magnitude of the voltage, also known as the potential, value and type of current flowing through the conductor, the power consumed by the load from the network, the resistance value (in Ohms) and some others.
To measure each of them, specialized instruments were created. For current, these are ammeters, for voltage - voltmeters, ohmmeters for resistance, etc. However, what if there is a need to measure not one parameter, but several at once? Carry all existing appliances with you? In this case, there is no need to talk about mobility and convenience. To solve this problem, universal solutions were created: devices that functionally combine several others at once. For example, by switching a special toggle switch to the first position, you can measure the voltage, while in the second, internal logic is used to determine the resistance. Conveniently! Such devices are known as multimeters. That is, "multi" - a lot, but "meters" - to measure. The second name, which is not entirely correct, is testers. Modern digital multimeters allow you to measure many parameters: from the simple resistance of a circuit section to the ambient temperature.
Modifications
Despite the great variety of these devices, they are all divided into two main classes: analog and digital multimeters. The latter are more convenient for most users, although the former have a number of advantages, though specific.
Graduated scale and arrow
Analog models have already been practically discontinued, as the demand for them turned out to be insignificant compared to the alternative option (the digital DT multimeter is now incredibly popular). However, in the markets you can still find new similar solutions, so we will briefly consider them. Analog devices are very easy to distinguish from others: on the case there is a ratchet switch designed to select the measurement mode, as well as a rather large panel with a scale on which the markings are marked (similar to a ruler). When probes are connected to a circuit, current is generated in the internal coils, magnetic fields are created and their interaction causes the pointing arrow to deviate by a certain angle. It remains only to calculate the division price and find out the value of the measured parameter. Digital multimeters are more preferable in this respect, since an error is excluded when recalculating the graduation of the scale under the limit set by the ratchet.
Display with numbers
Digital multimeters look almost the same as analog ones, except that the switch unit is replaced by a compact screen, which displays the measurement results. Internal changes, of course, are much more significant. A microcircuit is located on the printed circuit board , which performs complete processing of the signal received from the probes. Often, several elements are additionally used - resistors, capacitors and coils. Among the distinctive features of these solutions, it is worth noting a slight measurement error - a high accuracy class that is inherent even in budget models, for example, such as a digital 838 multimeter.
Summarizing
For a person who occasionally needs to measure some parameters of the electrical circuit at home or, for example, in the on-board system of a car, an inexpensive digital tester is the best choice. It is enough to understand the rules for using a ratchet and understand the principle of choosing the limits of measurement.