Ametek CEM/Humox, User Manual

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5-2 | Thermox CEM/Humox Analyzer
Definitions
When discussing calibration operations, you should be aware of the following
definitions:
Calibration vs. Verification Operations
The Series 2000 control unit software refers to both calibration and verification
operations. The difference between a calibration and a verification operation is as
follows. During a verify operation, the calibration gas readings are taken, and the
difference between what the system records for the gas values and their known values
is recorded. Internal calibration parameters are not changed. Verify operations are
often used to check that the instrument is running within required tolerances. Dur-
ing a calibration operation, software algorithms adjust the difference between the
current readings and the known calibration gas values until they are equal. When we
speak in this chapter about a calibration in a general sense, we are actually referring
to either a verification or a calibration.
Span vs. Zero Gas
This chapter also refers to the terms span and zero calibration gases. The span gas
is the high calibration gas. The zero gas is the low calibration gas.