Dc resistance tester is a convenient and effective test to inspect the winding insulation and current loop connection of electrical equipment. By measuring the DC resistance, you can check the welding or connection quality of the lead, whether the winding is short or open between turns, and whether the contact of the tap switch is good.
According to "GB26860-2001 Power safety work regulations" provisions, transformer in the handover, overhaul, minor repair, change tap location fault and preventive test, dc resistance test must be carried out. In the past, single-arm and double-arm Bridges were used to measure the main resistance. The measuring current of this kind of bridge is milliampere level, and the measuring process is time-consuming and the accuracy is low. The appearance of the current resistance tester shortens the measuring time and effectively reduces the workload of the tester.
Dc resistance tester in addition to superior performance, good reliability, easy to use and other characteristics, can also be used as 1μV~2V voltage measurement, as well as testing small motor, transformer winding resistance, widely used in laboratories, mining sites and other places, is an ideal DC resistance measurement instrument.
Dc resistance tester adopts typical four-wire measurement method. In order to improve the accuracy of measuring resistance (especially low resistance). Program-controlled constant current source, program-controlled preamplifier and A/D converter constitute the main body of the measuring circuit. The central control unit applies a constant and high-precision current to the external load to be tested by controlling the constant current source. Then, the obtained data (including test voltage, current test current, etc.) are processed to obtain the actual resistance value.