Determination the Temperature Coefficient of Karma ResistorUsed in the Impulse Divider High Voltage Arm
PAN Yang1,ZHOU Li-ren1,XU Feng1,QIN Yi1,ZHAO Ye-ming2,PAN Jin-qiu2,SHAO Hai-ming3
1. Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China
2. Beijing Information Scienceand Technology University, Beijing 100192, China
3. National Institute of Metrology, Beijing 100029, China
Abstract The Karma resistor, which is used in the high-voltage arm of the high-voltage impulse divider, needs to be uniformly wrapped around the insulating skeleton. However, the introduction of the skeleton will affect the temperature coefficient of Karma resistor. Two dominant factors which affect the temperature coefficient are demonstrated, one is the thermo expansion coefficient of skeleton, the other is the bending strain caused by geometry structure of the skeleton. When the thermal expansion coefficient of the skeleton is larger than that of the material itself, the measurement result of the temperature coefficient will be larger than the true temperature coefficient of the resistance, bending strain will cause the destruction of the K-state structure and make the resistance value decrease.
PAN Yang,ZHOU Li-ren,XU Feng, et al. Determination the Temperature Coefficient of Karma ResistorUsed in the Impulse Divider High Voltage Arm[J]. Acta Metrologica Sinica, 2018, 39(6): 822-825.
2018, Vol. 39 
