User's Manual

General Troubleshooting & Repair of the M400E Analyzer M400E Ozone Analyzer Operator’s Manual
 Confirm the sample pressure, sample temperature, and sample flow readings are correct and have
steady readings.
 Verify that the sample filter element is clean and does not need to be replaced.
13.5.3. INABILITY TO SPAN – NO SPAN KEY (CALS)
 Confirm that theO
3
span gas source is accurate. This can be done by inter-comparing the source with
another calibrated monitor, or having theO
3
source verified by an independent traceable photometer.
 Check for leaks in the pneumatic systems as described in Section 12.3.4.

Make sure that the expected span gas concentration entered into the instrument during calibration is not
too different from expected span value.
 Check to make sure that there is no ambient air or zero air leaking into span gas line.
13.5.4. INABILITY TO ZERO – NO ZERO KEY (CALZ)
 Confirm that there is a good source of zero air. If the IZS option is installed, compare the zero reading
from the IZS zero air source to the calibration zero air source.
 Check for leaks in the pneumatic systems as described in Section 12.3.4.

Check to make sure that there is no ambient air leaking into zero air line.
13.6. OTHER PERFORMANCE PROBLEMS
Dynamic problems (i.e. problems that only manifest themselves when the analyzer is monitoring sample gas)
can be the most difficult and time consuming to isolate and resolve. The following section provides an itemized
list of the most common dynamic problems with recommended troubleshooting checks and corrective actions.
13.6.1. TEMPERATURE PROBLEMS
Individual control loops are used to maintain the set point of the UV Lamp, IZS Ozone Generator (Optional) and
Metal Wool Scrubber (Optional) temperatures. If any of these temperatures are out of range or are poorly
controlled, the M400E will perform poorly.
13.6.1.1. Box Temperature
The box temperature sensor is mounted to the Motherboard and cannot be disconnected to check its resistance.
Rather check the
BOX TEMP signal using the SIGNAL I/O function under the DIAG Menu (see Section 13.1.2).
 This parameter will vary with ambient temperature, but at ~30
o
C (6-7 above room temperature) the
signal should be ~1450 mV.
13.6.1.2. Sample Temperature
The Sample Temperature should read approximately 5.0C higher than the box temperature.
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