Teledyne 9110E - Nitrogen Oxides Analyzer - Manual (Page 88)

Operating Instructions Model 9110E Instruction Manual
74 M9110E Rev B
6.7.5. Optic Test
The optic test function tests the response of the PMT sensor by turning on an LED located in
the cooling block of the PMT (Fig. 10-15). The analyzer uses the light emitted from the LED
to test its photo-electronic subsystem, including the PMT and the current to voltage
converter on the pre-amplifier board. To make sure that the analyzer measures only the
light coming from the LED, the analyzer should be supplied with zero air. The optic test
should produce a PMT signal of about 2000±1000 mV. To activate the electrical test press
the following key sequence.
SAMPLE RANGE = 500.0 PPB NOX=X.X
< 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
EXIT
DIAG SIGNAL I / O
PREV NEXT JUMP
ENTR EXIT
DIAG OPTIC RANGE = 500.0 PPB NOX=X.X
EXIT
SETUP X.X ENTER DIAG PASS: 818
8 1 8
ENTR EXIT
Press NEXT until…
DIAG OPTIC TEST
PREV NEXT
ENTR EXIT
Press TST until…
DIAG ELEC PMT = 2751 MV NOX=X.X
EXIT
While the optic test is
activated, PMT should be
2000 mV ± 1000 mV
NOTE
This is a coarse test for functionality and not an accurate calibration tool. The
resulting PMT signal can vary significantly over time and also changes with low-
level calibration.
6.7.6. Electrical Test
The electrical test function creates a current, which substitutes the PMT signal, and feeds it
into the preamplifier board. This signal is generated by circuitry on the pre-amplifier board
itself and tests the filtering and amplification functions of that assembly along with the A/D
converter on the motherboard. It does not test the PMT itself. The electrical test should
produce a PMT signal of about 2000 ±1000 mV.