TEMPERATURE CONTROL DEVICE FOR HUMIDITY SENSOR

摘要

PROBLEM TO BE SOLVED: To provide a temperature control device for a humidity sensor, in which the cracking of a sensor element caused by heat from a heater under a condensation state is prevented, impurities adhered to the sensor element are efficiently and sufficiently removed, and the adhesion of the impurities to the sensor element is suppressed, so as to keep the detection accuracy of a humidity sensor excellent. SOLUTION: The temperature control device 1 for the humidity sensor controls temperatures THCM, THCM2 of sensor elements 18a, 30a of the humidity sensors 18, 30 that are arranged in an exhaust pipe 3 of an internal combustion engine 2 to detect humidity in the exhaust pipe 3. The control device comprises: heaters 19, 35 for heating the sensor elements 18a, 30a; temperature detecting means 20, 31 for detecting the temperatures of THCM, THCM2 of the sensor elements 18a, 30a; a heater control means 25 for operating the heaters 19, 35 when the detected temperatures THCM, THCM2 of the sensor elements 18a, 30a are higher than a first predetermined temperature Tref1.