Teledyne 9110EH - Nitrogen Oxides Analyzer - Manual (Page 133)

Model 9110EH Instruction Manual Calibration Procedures
If the ZERO or SPAN keys are not displayed during zero or span calibration, the measured
concentration value is too different from the expected value and the analyzer does not allow
to zero or span the instrument. Consult Section 11.3 for calibration problems.
7.3. Calibration Checks
Informal calibration checks, which only evaluate but do not alter the analyzer’s response
curve, are recommended as a regular maintenance item and in order to monitor the
analyzer’s performance. To carry out a calibration check rather than a full calibration, follow
these steps.
Connect the sources of zero air and span gas as shown in Figure 7-2, then perform the
zero/span calibration check procedure:
SAMPLE NOX STB=XXX.X PPB NO2=X.XX
< TST TST > CAL
SETUP
ACTION:
Record the NO
X
,
NO
2
& NO
readings.
ACTION:
Supply span gas to the instrument
SAMPLE NOX STB=XXX.X PPB NO =X.XX
< TST TST > CAL
SETUP
ACTION:
Record the NO
X
,
NO
2
& NO
readings.
Wait until NOX
STB is below
0.5 ppb. This
may take
several minutes.
The value of NOX
STB may jump
significantly.
Wait until it falls
below 0.5 ppb. This
may take several
minutes.
SAMPLE NOX STB=XXX.X PPB NO = X.X
< TST TST > CAL SETUP
The SPAN key appears during the transition from zero to
span. You may see both keys.
SAMPLE RANGE = 500.0 PPB NOX=X.XX
< TST TST > CAL SETUP
Scroll the display to the
NOX STB test function.
ACTION:
Supply the instrument with zero gas.
7.4. Calibration with Zero/Span Valves
To perform a manual calibration or calibration check of the analyzer with a zero/span valve
option installed and functioning, use the following method. The basic differences between
calibrating an M9110EH with the zero/span valve option instead of the basic calibration
method (Section 7.2) are that zero air and span gas are now supplied through dedicated
gas inlets rather than through the sample inlet and that the zero and span operations are
initiated directly and independently with dedicated keys CALZ and CALS.
M9110EH Rev 0 119