A new temperature measurement method using a giant magnetoresistance (GMR) sensor based on Johnson noise thermometry (JNT) is proposed in this paper. This paper presents the principle of this GMR-based JNT and demonstrates its feasibility by measuring power spectral density of noise voltage in the bandwidth from 10 kHz to 22.8 kHz and resistance of GMR sensor and analyzing their relationship with the absolute temperature. The measuring errors throughout the measurement of temperature from -40 °C and 150 °C in the thermal chamber were less than ±1.8 °C with integration time of 58.6 s. Its dynamic sensing performance under both varying temperature and changing external magnetic field was characterized and demonstrated. A practical demonstration of the GMR-based JNT for measurement of surface temperature of a battery pack on an electric-vehicle testbed was also provided. Therefore, it is feasible to implement this new thermometry with a GMR sensor, making spintronic sensor multifunctional in EV applications by being a temperature sensor as well.
All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering
- electric vehicle
- GMR sensor
- Johnson noise thermometry (JNT)
- multifunctional spintronic sensor