Ametek 241CE II User Manual page 152

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RUN Mode
ApplicCFGMTLo
RUN ModeApplicCFG
MTHi
6-2 | 241CE II Hydrocarbon Dewpoint Analyzer
To verify the analyzer is functioning properly:
1. Prepare the analyzer for functional verification:
a. Close the isolation valve on the Sample Probe or at the Sample Inlet valve.
b. Open the Bypass Valve, if not already done, and allow the gas pressure in
the sample system and Measuring Cell to depressurize for approximately
5 minutes.
c. Disconnect the Sample Line from the analyzer at the Filterblock Assembly,
and then remove the 1/3 PSIG check valve temporarily. The check valve
must be removed for this procedure and then replaced before recon-
necting the Sample Line and resuming normal sample operations.
2. Prevent the analyzer from cycling through the measuring cycle by setting
the mirror Low setpoint temperature (MTLo) to 0.5 degrees below the mir-
ror High setpoint temperature (MTHi). This will help maintain a relatively
constant temperature in the Measuring Cell and will prevent premature
condensation of the propane while setting up the test.
3. Connect an accurate pressure gauge and a manual valve to the inlet of the
Filterblock Assembly. Locate the gauge between the filter and the valve.
4. Next, connect an instrument grade propane tank (with a regulator and
shut-off valve) to the inlet of the manual valve.
5. With the Bypass Valve in the closed position, thoroughly flush the Measur-
ing Cell with propane to remove all traces of process stream gas or air. This
flushing is best accomplished by adjusting the Purge cycle flow rate in the
range of 1.0–5.0 Nl/minute or 2.1–10.6 SCFH and allowing the analyzer to
purge the sample system for at least 20 minutes. The propane pressure is
adjusted to the desired value.
Adjust the pressure of the propane to the equal that on the Vapor Pres-
sure of Propane tables (Figures 6-1 and 6-2).
The pressure on the gauge must be set at "gauge" pressure not "abso-
lute" pressure. To determine gauge pressure, subtract the barometric
pressure from the absolute pressure.
PN 903-8797, Rev A