Teledyne T802 Operation Manual page 208

Troubleshooting and Service
11.3.2.2. LOW FLOW
11.3.2.3. HIGH FLOW
11.3.2.4. DISPLAYED FLOW WARNINGS
206
Teledyne API T802 Paramagnetic O
4. If gas flows through the instrument when it is disconnected from its sources
of zero air, span gas or sample gas, the flow problem is most likely not
internal to the analyzer. Check to ensure that:
 All calibrators/generators are turned on and working correctly.
 Gas bottles are not empty or low.
 Valves, regulators and gas lines are not clogged or dirty.
1. Check if the pump diaphragm is in good condition. If not, rebuild the pump
(See Section 10.3.2). Check the Spare Parts List for information on pump
rebuilding kits.
2. Check for leaks as described in Section 10.3.3. Repair the leaking fitting, line
and re-check.
3. Check for the sample filter and the orifice filter for dirt. Replace filters (See
10.3.1).
4. Check for partially plugged pneumatic lines. Clean or replace them.
5. Check for plugged or dirty critical flow orifices. Replace them.
The most common cause of high flow is a leak in the sample flow control. If no
leaks or loose connections are found in the fittings or the gas line between the
orifice and the pump, replace the critical flow orifice inside the sample flow
control assembly.
This warning means that there is inadequate gas flow. There are four conditions
that might cause this:
 A leak upstream or downstream of the flow sensor
 A flow obstruction upstream or downstream of the flow sensor
 Bad Flow Sensor Board
 Bad pump
To determine which condition is causing the flow problem, view the sample
pressure and sample flow functions on the front panel display. If the sample
pressure is reading abnormally low, then the cause is likely a flow obstruction
upstream of the flow sensor. First, check the sample filter and make sure it is not
plugged and then systematically check all the other components upstream of the
orifice to ensure that they are not obstructed.
If the sample pressure is reading normal but the sample flow is reading low, then
it is likely that the pump diaphragm is worn or there is an obstruction downstream
of the flow sensor.
Analyzer Operation Manual
2
07275B DCN6418