Patent ID: 7407323

Claim:
A method of detecting a temperature T O of a remote object, said method comprising: measuring an output of an infrared sensor directed toward the remote object at two temperatures of the remote object and a temperature T A proximate the infrared sensor; determining calibration coefficients S and B from the measured output at the two temperatures; determining a voltage output of a temperature sensor, the voltage output corresponding to the temperature T A , V(T O , T A ); generating a lookup table relating the output voltage of the infrared sensor to the temperature sensed by the infrared sensor, V(T O , T A ) versus the temperature T O of the object at a plurality of temperatures using the determined values of S and B; storing the lookup table in a memory; determining a temperature sensor voltage output corresponding to a temperature T A proximate the infrared sensor; determining a first voltage as a function of the temperature T A proximate the infrared sensor and a reference temperature T REF , V(T A , T REF ); determining a second voltage as a function of the temperature of the object T O and the reference temperature T REF , V(T O , T REF ) by combining the determined temperature sensor voltage output and the first voltage; and determining a temperature of the object T O from the lookup table using the second voltage.