Teledyne 9110T - Nitrogen Oxides Analyzer User Manual

Page 206

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Model 9110T NOx Analyzer

Calibration Procedures

Teledyne Analytical Instruments

206

9.3.5. PERFORMING A MANUAL CALIBRATION WITH THE INTERNAL

SPAN GAS GENERATOR

If the analyzer’s reporting range is set for the AUTO range mode, a step will appear for selecting which
range is to be calibrated (LOW or HIGH). Each of these two ranges MUST be calibrated separately.

9.3.5.1. Setting the Expected Span Gas Concentration

Note

The expected concentrations for both NOx and NO are usually set to the
same value unless the conversion efficiency is not equal to 1.000 or not
entered properly in the conversion efficiency setting.

When setting expected concentration values, consider impurities in your
span gas source (e.g. NO often contains 1-3% NO

2

and vice versa).

When calibrating the instrument using the internal permeation tube as a span gas source, it is necessary
to know, as close as possible, the concentration value of the gas being outputted by the tube. To
determine this value:

1. Perform a precision calibration of the instrument as describes in Section 9.3.1.

3. Perform a calibration check as described in Section 9.3.4.

 Record the value displayed for NO/NOx during the span check portion of the procedure.

 This will be the concentration value used in subsequent calibrations using the internal span

gas source.

 It is a good idea to measure the permeation tube output once every 4 to 6 months.

4. Ensure that the reporting range span point is set for a value at least 10% higher than the measured

value of the permeation tube output

To set the span gas concentration, press:

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