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Teledyne API Model 201A NH
3
Analyzer Instruction Manual, 04689, Rev. B1
2.1.1 Zero/Span Calibration with Z/S Valves or ECO Option
The zero gas enters through the zero gas inlet port on the rear panel. Make sure that
the umbilical cord that makes the control connections between the analyzer and the
converter is connected (see Figure 2 below). The zero gas valve can be activated by a
variety of methods discussed in Section 7 of the M200A manual. The example below
will use the front panel keyboard to activate the valves.
Table 2.4 - Zero Calibration Procedure - Zero Gas from rear panel zero air inlet
Step No.
Action Comment
1. Press
CALZ
The M201A enters the calibrate mode from
sample mode. The zero gas is supplied
through the zero air inlet port on the rear panel.
2. Wait 20
min
Wait for reading to stabilize at zero. If the
instrument has recently been exposed to high
levels of NH3, you may need to wait up to 2
hours for the instrument to return to zero.
3. Press
ZERO
If you change your mind after pressing ZERO,
you can still press EXIT here without zeroing
the instrument.
4. Press
ENTR
Pressing ENTR actually changes the
calculation equations.
5. Press
EXIT
M201A returns to sampling. This switches the
ZS valves so that sample gas is coming in the
sample port on the rear of the instrument.
Immediately after calibration, data is not added
to the DAS averages.
Since the zero gas concentration is defined as 0 ppb, it is not necessary to enter the
expected zero value.
The expected value of the span gas is entered into the instrument by the following
procedure.
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