Verifying Gas Concentrations; Verification - Emerson Rosemount CT4400 Reference Manual

Reference Manual
00809-0100-4244
5

Verifying gas concentrations

5.1

Verification

Verification flows the known gas concentration through the analyzer and gives you a
display of the measurement, the cylinder value, and the difference between the two. You
can use verification to confirm that the analyzer is within tolerance. If it is out of tolerance,
perform a calibration (see Calibration).
5.1.1 Zero verification
Zero verification confirms that when no sample gas is flowing through the analyzer, the
gas concentrations measured by the analyzer are zero. To zero verify, compare the
analyzer measurements to a known sample gas using the following procedure:
Procedure
1. Use nitrogen gas of instrument gas purity as the zero verification gas.
2. Ensure that a pressure regulator is connected to the nitrogen gas bottle.
3. Connect a hose from the nitrogen gas bottle through a T-piece to the sample supply
4. Connect an excess flow line to the unused port on the T-piece and route the excess
5. To ensure an accurate zero measurement, the analyzer must have been switched
6. On the display controller of the analyzer select the Main Menu screen.
7. Scroll
Reference Manual
port on the rear of the analyzer.
flow line to a suitable extractor.
on for a minimum of 30 minutes prior to verifying the reading.
and select GAS SERVICE. Press
or
Figure 5-1: Gas Service
Verifying gas concentrations
January 2020
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