Measuring method of DC resistance tester:

Measuring DC resistance is an important item in the transformer experiment. After measurement, it is possible to check whether the conductive circuit of the equipment has defects such as poor contact, poor welding, coil faults, and wiring errors. In the actual measurement of medium and small transformers, most of the DC bridge method is used. When the resistance value of the tested coil is above 1 ohm, a single-arm bridge is generally used for measurement, and the double-arm bridge is used for measurements below 1 ohm. When using double-arm bridge connection, the potential pile head of the bridge should be close to the resistance to be measured, and the current pile head should be connected to the potential pile head. Before measurement, you should first estimate the resistance value of the coil under test, place the bridge magnification button in the appropriate position, short-circuit the non-test coil and ground, then turn on the power switch to charge, and press the galvanometer switch after it is fully charged. Quickly adjust the measuring arm, move the pointer of the galvanometer to the zero line of the center of the galvanometer scale, make fine adjustments, and record the resistance value when the pointer stops at the zero position. At this time, the resistance value of the measured coil = the multiplication number × Measuring arm resistance value. After the measurement is completed, first open the galvanometer button, and then release the power switch.