Loop type resistance testing instrument

The utility model relates to a loop resistance resting instrument for the electrician testing technology. The utility model is characterized in that the complete machine is composed of a power supply part and a control part; the power supply uses the high and low power supplying working power supplies; the utility model adopts the high-frequency transformer with pulse width modulation and amplification and high magnetic flux of 200A power supply to output; the control part is composed of an operational amplification, a CPU control circuit, an analog-digital conversion circuit, a display circuit, a printing circuit and a real time control circuit. The utility model has the advantages of small volume, large electric and constant current source, and effectively reduces the influence on the test result when the alternating current fluctuates and. The loop resistance test can continuously sample 12 times, and the measuring accuracy rate is improved.