Ametek Thermox WDG-VRM, Руководство пользователя

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8-2 | Thermox WDG-V RM
general Troubleshooting
Your system may pass calibrations, yet still seem to be reading incorrect oxygen
levels. If this is the case, you may want to check the following:
leak Check
Leaks can lead to inaccurate readings, especially if operating under a significant
pressure or vacuum.
• Check that all compression fitting and pipe thread connections are leak tight.
sniffing for leaks
For processes under vacuum you can check for leaks by sniffing the fittings with
another gas (for example, nitrogen or pure oxygen), being sure to avoid the area
over the top of the cell.
1. Use a piece of tygon or plastic tubing with a 1/8” stainless steel nozzle to ap-
ply the gas from a cylinder (using stainless steel prevents any problems that
might occur with plastic melting the nozzle on hot sensor components).
2. Monitor the response from the cell. When the cell millivolt reading changes,
it indicates a leak in that area of the plumbing (the vacuum of the process
pulls in the gas).
3. If not convenient to view the control unit display, you can also apply a volt-
meter to the Cell terminals on the sensor board labeled (+O
2
-) to see if the
cell millivolts change, indicating a leak.
Pressurizing for leaks
1. Remove the sensor from the process (after allowing sensor to cool) and pres-
surize it with 5 lbs. of air, plugging any exiting ports, the inlet probe, and
exhaust tube holes. Then go over the sensor fittings with a leak detector fluid.
2. If you see bubbles, it indicates a leak. If using this method be sure to prevent
the liquid from reaching the furnace. If the furnace does get wet, allow it
sufficient time to thoroughly dry.