Non-contact Current Measurement in Small Electric Parts by Using a Non-contact Thermometer

This paper describes a non-contact current measurement in small electric parts by using a non-contact thermometer. When the small electric parts are used in a small machine or device, it is difficult for a conventional current sensor to measure current in the small electric parts. Assuming that the temperature rise of the parts is proportional to the power consumption, the temperature rise and the resistance of the parts are used to obtain the current through the electric parts. In our experiment, the relationship between the current, temperature rise and power consumption is clarified. The power consumption is proportional to the temperature rise and the current is in proportion to the square root of the temperature rise. The method how to measure the current without contact is explained.