Patent ID: 9557751
Date: 2017-01-31
CPC Classifications: G01N,G05D

Claim:
1. A sensor temperature control apparatus used for a sensor having a sensor element section and a heater section for heating the sensor element section and adapted to control temperature of the sensor element section by controlling pulse energization of the heater section, the sensor temperature control apparatus comprising: a switching device which allows and prohibits supply of electricity to the heater section; energization control means for feedback-controlling a duty ratio of an energization control pulse signal input to the switching device such that the sensor element section is maintained at a target temperature; storage means for storing in advance a first duty ratio which is the duty ratio in an un-shorted constant temperature state in which all current flowing through the switching device flows through the heater section and the sensor element section is maintained at the target temperature; element temperature judgment means for determining whether or not the temperature of the sensor element section falls within a first temperature range including the target temperature; and semi-shorted state detection means for comparing a present duty ratio which is the duty ratio at present with the previously stored first duty ratio in a state in which the temperature of the sensor element section falls within the first temperature range, to thereby determine whether or not there has arisen a semi-shorted first temperature range state in which only a portion of the current flowing through the switching device flows through the heater section and the temperature of the sensor element section falls within the first temperature range.