Teledyne GFC-7000T - Trace CO2 Analyzer - manual - Manual (Page 155)

Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer
Teledyne Analytical Instruments 137
6.13.6. Dark Calibration Test
The dark calibration test interrupts the signal path between the IR photo-detector and the remainder of
the sync/demod board circuitry. This allows the instrument to compensate for any voltage levels inherent
in the sync/demod circuitry that might effect the calculation of CO
2
concentration. Performing this
calibration returns two offset voltages, One for CO
2
MEAS and on for CO
2
REF that are automatically
added to the CPU’s calculation routine. The two offset voltages from the last calibration procedure may
be reviewed by the user via the front panel display.
To activate the dark calibration procedure or review the results of a previous calibration, press:
SETUP X.X ENTER DIAG PASS: 818
8 1 8
ENTR EXIT
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
Calibration runs automatically
Electric offset for Measurement signal
Electric offset for Reference signal
DIAG SIGNAL I / O
NEXT ENTR EXIT
Repeat Pressing NEXT until . . .
DIAG DARK REF DARK OFFSET: 0.0 mV
EXIT
DIAG DARK MEAS DARK OFFSET: 0.0 mV
EXIT
DIAG DARK DARK CAL 1% COMPLETE
EXIT
DIAG DARK DARK CALIBRATION ABORTED
EXIT
Display
tracks %
complete
DIAG DARK CALIBRATION
PREV NEXT ENTR EXIT
Exit returns
to the
previous menu
DIAG DARK CO2 DARK CALIBRATION
VIEW CAL EXIT