The principle of operation of the meter type IMI-413Z is based on the operation of a series ohmmeter with a magneto-electric measuring system.
The measuring system is powered by direct current from a built-in alternator, driven manually. As a result, the instrument does not require other sources of energy and is therefore always ready for use.
The meter's readings do not depend on the alternator's crank speed, as the instrument is equipped with a mechanical speed stabilizer.
The high power of the alternator makes it possible to measure the insulation resistance of long cable lines, where the electrical systems conductor - armor or conductor - conductor, have a significant electrical capacitance, which charges at the expense of energy from the power source. The charging time of a circuit with a capacitance of 1 μF is only 20 to 30 seconds.Practically, this means that when measuring such specific electrical systems, it is possible to take a correct reading of the result from the instrument's scale as early as 30 seconds after the start of the measurement.
In order to eliminate the influence of changes in influential quantities, such as temperature, on the indications of the meter, it is equipped with a special knob, with which, if necessary, you can make the necessary correction before the measurement.
The IMI-413Z meter has two measurement ranges, selectable by a rotary switch.
The instrument is equipped with a special handle and a case, so that it can be conveniently carried.