For Calibration of Endurance the following sequence is recommended:
1. Calibration of the analog output See Article
2. Setting up the sensor with a reference source - distance, aperture, focussing and general procedures.
Articles:
a. Focus reference point See Article
b. Factory calibration geometry for popular models See Article
c. Basic calibration procedure See Article
Special Note:
Is essential for the calibration of ratio or two color sensors, that in-house calibration equipment users are able to verify that whichever IR calibration tool in use does not have a minute difference in output at the two operating wavelengths.
Over time an IR calibrator using a graphite tube purged by inert gas will experience degradation in the graphite tube exhibit a "slope error" when calibrating two color or ratio sensors.
The could result in a new unit would for the "2C" reading be out of specification, often compared to the "1C" or "wide band" or "top detector". Any adjustments performed to bring the "2C" reading into compliance will be erroneous.
Further confusion may arise after performing such an adjustment and subsequently replacing the graphite tube, the previous sensor would then be classed as out of specification again.
We recommend the use of a dedicated calibrated 2 colour instrument to track the degradation by recording and logging the following Endurance E1R readings over time:
Narrow band temperature (1C reading - available via software or display)
Wide band temperature (only available via software)
The general theory is that when the graphite tube is new, the narrow and wide band temperatures are virtually the same.
The tube should be replaced when these two values differ by more than: To Be Confirmed