Long-Term Stability of Thermometric Thermistor Sensor SKLFSE-TS Used at Low Temperature

In this paper,the thermometric thermistor sensor SKLFSE-TS for single-point and multiple-point temperature monitoring is described in detail.One thermometric system including eight sensors was put into a borehole in 2003,and then taken out and re-calibrated in laboratory at August,2010.The calibration device and calibration temperatures of the sensors in first calibration and re-calibration are completely the same.Then,the inverse calculation temperature can be obtained using the resistance values at 2010 and calibration coefficient at 2003 for each temperature sensor.A temperature drift between the first calibration and the re-calibration is found.The temperature drift values of all sensors are positive,with a maximum of 0.032 ℃,which is lower than the precision of the sensor,0.05 ℃.Thus,the long-term stability of thermistor sensor SKLFSE-TS used in permafrost regions is qualified.