Teledyne API Model 201A NH3 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 | The M201A enters the calibrate mode from |
| CALZ | sample mode. The zero gas is supplied |
|
| through the zero air inlet port on the rear panel. |
2. | Wait 20 | Wait for reading to stabilize at zero. If the |
| min | 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 | If you change your mind after pressing ZERO, |
| ZERO | you can still press EXIT here without zeroing |
|
| the instrument. |
4. | Press | Pressing ENTR actually changes the |
| ENTR | calculation equations. |
5. | Press | M201A returns to sampling. This switches the |
| EXIT | 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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