Temperature and Resistance Standards
The Calibration System involves both temperature and resistance measurements.
UW SSEC maintains a calibrated Guildline 9540 PRT for use as a Transfer Standard.
This PRT instrument is used as a Transfer Standard between the Rosemont 162CE SPRT (Maintained at Guildline) and the AERI Blackbody thermistors.
UW SSEC maintains a set of calibrated resistors with values corresponding to the expected range of thermistors.
These calibrated resistors are used in the end to end calibration of the AERI thermistor resistance reading electronics.
This end-to-end calibration involves all the hardware and software that make up the AERI thermistor reading electronics.
The calibration of each resistance measurement channel results in a linear regression fit over the resistance measurement range.
The AERI blackbody thermistors could be calibrated using the Transfer Standard PRT and an uncalibrated resistance measurement electronics. However, this scheme would not allow blackbodies to be interchangeable between different sets of electronics - the blackbodies would have to be used only with the resistance measurement system that they were calibrated with. This constraint is very undesirable if there are several instruments in various locations in the field, without access to calibration facilities (temperature chambers).