Teledyne GFC-7000T - Trace CO2 Analyzer - manual - Manual (Page 156)

Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
Teledyne Analytical Instruments 138
6.13.7. Pressure Calibration
A sensor at the exit of the sample chamber continuously measures the pressure of the sample gas. This
data is used to compensate the final CO
2
concentration calculation for changes in atmospheric pressure
and is stored in the CPU’s memory as the test function PRES (also viewable via the front panel).
NOTE
This calibration must be performed when the pressure of the sample gas is equal
to ambient atmospheric pressure.
Before performing the following pressure calibration procedure, disconnect the
sample gas pump and the sample gas-line vent from the sample gas inlet on the
instrument’s rear panel.
To cause the analyzer to measure and record a value for PRES, press.
SAMPLE RANGE = 500.000 PPM CO2 =X.XXX
< TST TST > CAL SETUP
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG ALRM EXIT
Adjust these values until the
displayed pressure equals the
pressure measured by the
independent pressure meter.
DIAG SIGNAL I / O
NEXT ENTR EXIT
Exit at
any time
to return
to main
the
SETUP
menu
SETUP X.X ENTER DIAG PASS: 818
8 1 8
ENTR EXIT
Repeat Pressing NEXT until . . .
DIAG PCAL ACTUAL PRESS : 27.20 IN-HG-A
2 7 .2 0 ENTR EXIT
ENTR accepts the
new value and
returns to the
previous menu
EXIT ignores the
new value and
returns to the
previous menu