Ndir Analyzer Measurement Cell; System Self Diagnostic Test - Teledyne 7120 Operating Instructions Manual

Photometric ir analyzer

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Infrared Analyzer

5.3 NDIR Analyzer Measurement Cell

The Infrared Analyzer contains an auto zero circuit which

automatically zeroes the analyzer. This zeroing compensates for dirt in the

sample cell and, under normal circumstances, will compensate for very large

amounts of contamination in the cell. If there is a need for removing the cell

and cleaning it, follow this procedure:

A) Turn off power to the analyzer and open the optical bench

housing. Disconnect the cell heater wires (if present).

B) Remove the cell assembly from the optical bench. Non-sealed

cells can be swabbed with water and alcohol and dried thoroughly before

reassembly. Sealed cells can be blown out with air, washed, or replaced.

C) After the cells have been cleaned and thoroughly dried,

reassemble them into the optical bench. Also attach any disconnected wiring

back onto the bench and check all connections and fasteners.

D) Turn on the analyzer and allow it to warmÄup for at least ten

minutes. Check for zero and span gas response.

NOTE: Typically, sample cell should only be removed for cleaning

when the Auto Zero circuit can no longer com~ensate for offset or if there is

a loss of sensitivity caused by cell lnefficiency .

5.4

1. Press the System button to enter the system mode.

2. Use the < > arrow keys to move to More, and press Enter.

3. Use the < > arrow keys to move to Self-Test, and press Enter.

The following failure codes apply:

Table 5-1: Self Test Failure Codes

Power

5 V Failure

Teledyne Analytical Instruments

Maintenance 5

5-3

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