Patent ID: 6907370

Claim:
A method of generating a calibration file for use with a measurement system, the method comprising performing a) through k) for each of a plurality of command signal setpoints: a) generating a digital control value corresponding to the command signal setpoint; b) converting the digital control value to a corresponding analog control value; c) applying the analog control value to a light source whereby the intensity of the light source depends upon the analog control value; d) measuring the intensity of the light source with an image capturing device; e) providing a measured intensity value to a comparator; f) determining a reference intensity value corresponding to the command signal setpoint; g) providing the reference intensity value to the comparator; h) comparing the reference intensity value to the measured intensity value; i) if the measured intensity value is lower than the reference intensity value, then incrementally increasing the digital control value applied to the light source and repeating b).through h); j) if the measured intensity value is higher than the reference intensity value, then incrementally decreasing the digital control value applied to the light source and repeating b) through h); and k) if the measured intensity value is within the acceptable tolerances, then recording the current digital control value and the corresponding command signal setpoint in a calibration file.