Patent ID: 7716962

Claim:
A method of calibrating a gas sensor that generates an output related to the concentration of a sensed gas, the method comprising: i) obtaining the value of said output or a related value at each of a set of known values of a first variable and at each of a set of known values of a second variable, one of the variables being gas concentration; ii) for each value of said second variable, determining a first best fit function relating said output or related value to the first variable, each best fit function utilizing at least one coefficient whose value is determined; iii) for the, or the corresponding, coefficient values from each of the first best fit functions, determining a second best fit function relating said coefficient to the second variable, and replacing the coefficient values in the first best fit functions by the second best fit function; and, iv) repeating step iii) for each further coefficient, if any, in the first best fit functions so as to generate a final function relating said output or related value and said first and second variables.