AMI 210BR, Руководство пользователя

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AMI Analyzer Manual Maintenance and troubleshooting
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7. Verify that the sensor has not been frozen, or cooked. Also verify that the exhaust is not pulling a
vacuum on the sensor.
Analyzer reads too high
1. Verify that there is no flow restriction in the vent line of the analyzer. Check it for mud-dauber wasps.
2. Increase the flow rate through analyzer by adjusting the metering valve - if the reading goes down it
indicates a leak in the incoming sample line or the cell block. Use “Snoop

” or equivalent to check all
the fittings back to the gas source. If the reading changes immediately, the leak is close by – if it only
changes after a while, it is further away. Check such things as welded fittings on pipelines.
3. Leak test all external fittings with “Snoop

” or equivalent.
4. Verify that the gas flow rate is correct. (0.1 to 2 SCFH)
5. Oxygen diffusion can be a serious problem. Verify that no plastic tubing or other plastic components are
used in the system, including diaphragms of pressure regulators, packing of valves etc. Verify the
analyzer calibration using air as the span gas.
6. Remove the cell (and short it with the metal shorting tag) and verify that the analyzer reads 0.00ppm - if
not, there is moisture or corrosion between the sensor contacts in the cell block; clean the contacts and
the area around them with isopropyl alcohol, dry with dry compressed air or nitrogen, then replace the
cap on the cell block again. Pressurize the system to line pressure (less than 150 psig) and leak check all
the fittings and tubing including the sensor block penetrations such as the sensor wire seals (nylon plugs
and epoxy seals on the top of the cell block).
NOTE: Be careful not to get soap solution on the PC boards!
Analyzer reads zero
1. Verify that the sensor is in the correct position, not upside down. If it is upside down, verify that the
membrane has not been punctured - i.e. there is no sign of electrolyte on the surface, and if not, put it
back the right way up. If you have left it this way for a while, it may take several hours to recover to a
low reading.
2. Verify that the cell block contacts are touching the sensor. Pull the sensor tab, and the contact should
hold the sensor with a gentle force. If not, the contacts may be bent. If they have been bent too much,
remove the sensor and gently bend them downwards so that they can again make contact.
3. Make sure that the gold plated contact wires are clean. If not, gently clean them with a Q tip or an
eraser. Do not use an abrasive cleaner, as it will remove the gold plating.
4. Check the output of the sensor with a DVM configured to measure current. Connect its leads to the two
gold rings on the back of the sensor - the center is ground. The output should be around 300 to 550
micro Amps in air (at 70
º
F). This will take a few minutes to stabilize as the sensor consumes oxygen
dissolved in its electrolyte. Replace the sensor if it does not read this amount. See sensor replacement
instructions under Maintenance.