Teledyne 7300a - NDIR analyzer - Manual (Page 73)

Infrared Gas Analyzer Maintenance 5
5-3 Teledyne Analytical Instruments
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 System Self Diagnostic Test
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: