Teledyne T400, Руководство пользователя, Страница: 125 / 177

083730400A DCN8130 Teledyne API – Model T400 O
3
Analyzer 123
5.7.6.2 NON-REPEATABLE ZERO AND SPAN
As stated earlier, leaks both in the T400 and in the external system are a common source
of unstable and non-repeatable readings.
• Check for leaks in the pneumatic systems as described in Section 5.6.3. Also
consider pneumatic components in the gas delivery system outside the analyzer
such as:
•
A change in zero air source such as ambient air leaking into zero air line, or;
• A change in the span gas concentration due to zero air or ambient air leaking into the
span gas line.
• Once the instrument passes a leak check, perform a flow check (see Section 5.6.6)
to make sure adequate sample is being delivered to the sensor assembly.
• 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.
5.7.6.3 INABILITY TO SPAN – NO SPAN BUTTON (CALS)
•
Confirm that the O
3
span gas source is accurate. This can be done by
inter-comparing the source with another calibrated monitor, or having the O
3
source
verified by an independent traceable photometer.
•
Check for leaks in the pneumatic systems as described in Section 5.6.3.
•
Make sure that the expected span gas concentration entered into the instrument
during calibration is the correct span gas concentration and 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.
5.7.6.4 INABILITY TO ZERO – NO ZERO BUTTON (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 5.6.3.
•
Check to ensure that there is no ambient air leaking into zero air line.
5.7.7 O
THER
P
ERFORMANCE
P
ROBLEMS
Dynamic problems (i.e. problems which only manifest themselves when the analyzer is
monitoring sample gas) can be the most difficult and time consuming to isolate and
resolve. The following provides an itemized list of the most common dynamic problems
with recommended troubleshooting checks and corrective actions.
5.7.8 T
EMPERATURE
P
ROBLEMS
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 T400 will perform poorly.