Error Correction for High Precision Temperature Sensor

The applications of temperature sensor have penetrated into the electric power, metallurgy, chemical industry, building materials, machinery, food, petroleum, etc. The requirement on the precision of temperature measurement is a very important parameter. However, various factors affect the measurement precise of temperature sensor. One of the errors is caused by the temperature difference between the sensor surface temperature and the ambient temperature. A temperature sensor is usually wire bonded to a test PCB board, and then it is usually covered by glue for lab measurement. This results in a large error between the temperature measured by the chip and the temperature of the environment. This paper introduces an error correction method to deal with this temperature difference. In addition, we propose a technique to stabilize the environment temperature of DUT (device under test). Theoretical analysis and experimental results show that the proposed method can effectively reduce the errors caused by the chip packaging and temperature variation of the environment.