Patent ID: 8748808

Claim:
A method for detecting a loss of calibration of a thermal imaging radiometer comprising an array of imaging microbolometers and a gauge microbolometer for detecting said loss of calibration, the method comprising the steps of: a) applying a first electrical stimulation to the gauge microbolometer which brings said gauge microbolometer to a first predetermined temperature in a steady-state thermal regime; b) applying a second electrical stimulation to the gauge microbolometer which brings said gauge microbolometer to a second predetermined temperature in a steady-state thermal regime, the first predetermined temperature and the second predetermined temperature being different, steps a) and b) being performed under substantially identical radiation exposure conditions; c) determining a measured ohmic responsivity of the gauge microbolometer, said measured ohmic responsivity being representative of a difference between said first and second electrical stimulations; and d) comparing the measured ohmic responsivity with a reference ohmic responsivity of the gauge microbolometer, and signaling a loss of calibration of the thermal imaging radiometer when said measured ohmic responsivity and said reference ohmic responsivity differ by more than a predetermined threshold.