Lexicon Letter P

Output of the maximum temperature measurement indicated by an instrument during the time duration for which this display mode has been active.

A type of detector in which the photons or quanta of energy interact directly with the detector to generate a signal.

is the ratio of the number of molecules to the number of molecules of remaining gas
components. This parameter is independent of the total pressure and temperature.

is the ratio of the mass of molecules to the mass of the molecules of all remaining gas components. This parameter is independent of the total pressure and temperature.

Thermal detector that has a signal generated by means of the pyroelectric effect wherein
changes in temperature of the detector generates an electrical signal.

A broad class of temperature measuring devices, originally designed to measure high
temperature, but some are now used in any temperature range. Includes radiation pyrometers, thermocouples, resistance pyrometers, and thermistors.