Appendix A
Glossary
Absolute Zero
The temperature (0 degrees Kelvin) of an object defined by the theoretical condition where the object has zero energy.
Accuracy
Maximum deviation, expressed in temperature units, or as a percentage of the temperature reading, or as a percentage of the full scale temperature value, or as a percentage of the target temperature, indicating the difference between a temperature reading given by an instrument under ideal operating conditions, and the temperature of a calibration source (per the ASTM standard test method E
Ambient Derating
Refer to Temperature Coefficient.
Ambient Operating Range
Range of the ambient temperature conditions over which the thermometer is designed to operate.
Ambient Temperature
Ambient temperature is the room temperature or temperature surrounding the instrument.
Ambient Temperature Compensation (TAMB)
Refer to Reflected Temperature Compensation.
ASTM
ASTM is an abbreviation for American Society for Testing and Materials.
Atmospheric Windows
The Atmospheric Windows is the infrared spectral bands in which the atmosphere best transmits radiant energy. Two predominant windows are located at 2 to 5 µm and at 8 to 14 µm.
Background Temperature
Temperature behind and surrounding the target, as viewed from the instrument.
