Patent ID: 7731418

Claim:
A method for calibrating a thermometer, said thermometer comprising a primary temperature sensor and a reference temperature sensor, said reference temperature sensor being positioned proximate to the primary temperature sensor and being responsive to an extraneous temperature affecting the primary temperature sensor, said method comprising: calibrating the reference temperature sensor, including controlling the temperature of the reference temperature sensor to a first temperature value, measuring a characteristic of the reference temperature sensor at said first temperature value, controlling the temperature of the reference temperature sensor to a second temperature value different than the first temperature value, measuring a characteristic of the reference temperature sensor at said second temperature value, deriving values of at least two different reference calibration coefficients of a reference calibration equation, the reference calibration equation relating the temperature of the reference temperature sensor to said at least two different calibration coefficients and the, measured characteristic of the reference temperature sensor, storing the derived values of said at least two different reference calibration coefficients to a memory of the thermometer; and calibrating the primary temperature sensor using said derived values of said at least two different reference calibration coefficients; wherein said calibrating the reference temperature sensor further includes controlling the temperature of the reference temperature sensor to a third temperature value different than the first and second temperature values, measuring a characteristic of the reference temperature sensor at said third temperature value, wherein said at least two different reference calibration coefficients comprises at least three different reference calibration coefficients, and further wherein said reference calibration equation is a non-linear equation; and wherein said reference calibration equation is the following equation: T s = a + b R + c R 2 where Ts is the temperature of the reference temperature sensor, R is the measured characteristic of the reference temperature sensor, and a, b, and c are the calibration coefficients of the reference temperature sensor calculated based upon the first, second and third temperature values and the corresponding measured characteristics.