SHB_U14 Chapter 8: Calibration
8-9
Initial calibration of Uras 14 IR detectors
Accessories • Zero gas
• Span gas for large measurement range
• Gas mix pump as needed
• PC with TCT
When should an
initial calibration be
performed?
• Change in configuration
• Set up of a new IR detector
• Change in large measurement range
• Installation of sample cell with different length
• Retrofit of optical filters
• Retrofit of filter cells
• Retrofit of sample/filter cells
• Retrofit of calibration cells
• Change in emitter performance
• Change in amplification
• Change in analyzer module installation location (vertical/horizontal)
• Change of temperature correction to temperature control and vice versa
• Change of components
• IR detector
• Emitter insert
Note • An initial calibration of each IR detector installed is performed at the factory. The
setting is made with dry gases.
• Perform the initial calibration only with the hood cover removed.
• The analyzer module should be in a location as free of vibration as possible.
• Prior to performing an initial calibration, perform an optical and phase alignment.
• The initial calibration should always be performed with test gases having a known
concentration.
• Span gas concentration:
70 to 110 % of the large measurement range
• Only perform the initial calibration approx. 60 minutes after the end of the warm-
up phase. (warm-up phase approx. 60 min)
Monitor using the Diagnostics/controller parameter variables menu, or TCT device
test.
• Linearization of initially calibrated IR detectors is automatic and is not
measurement range-dependent.
Perform postlinearization to check.
(Exceptions: This does not apply in case of preset polynomial linearization)
• Prior calibrations are cancelled by an initial calibration.
Any linearity placed in effect will remain unchanged. (e.g. linearity parameters will
be retained)
If, for example, no postlinearization can be performed (no mixture pump on site)
and an IR detector was changed, both postlinearization correction factors must be
set to 1 with TCT. This corresponds to the default setting
• After an initial calibration the calibration cell component must be redetermined.
• When installing a sample cell with a different length the new length must be
entered in the TCT "Detector correction parameter" menu.
Reason: Linearity would not be correct otherwise.
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