Advanced Micro Instruments, Inc.
Page 28
Troubleshooting
Analyzer does not power up.
1
. Recharge the batteries. Recharge them, and if they do not take a charge, replace the battery
board.
2. When charging, check that the charger is plugged into a receptacle and that the receptacle is itself
powered. The Green LED will glow if the batteries are being charged.
Analyzer reads too low
1
. Sensor is not calibrated. Flow span gas through it as described and adjust the span until the
analyzer reads appropriately.
2. If the new sensor still reads too low, check its calibration with air and read the span gas - the span gas
may be incorrect. If so, please see the section entitled “Calibration Troubleshooting” above.
3. If you cannot adjust the span enough to accomplish this, replace the sensor.
4. If the sensor seems to die quickly, it may be getting poisoned by excess acid or sulfur bearing gases such
as SO2 or H2S. If so use a more resistant sensor such as the T-4. The reduction in cell life is cumulative,
it depends both on the level of poison and the duration of the exposure
5. The span gas you are using is incorrect. Span the analyzer using natural air as the span gas, and
measure the span gas. If it reads incorrectly, replace it.
6. The tank of compressed air you are using is manufactured air whose oxygen content is not 20.9%.
Span the analyzer using natural air as the span gas, and measure the bottled air. If it reads
incorrectly, replace it with a tank of certified gas.
Analyzer reads too high
1.
Verify that there is no flow restriction in the vent line of the analyzer.
2. Increase the flow rate through analyzer - 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.
3. Leak test all external fittings with “Snoop ” soap solution or equivalent.
4. Oxygen diffusion can be a serious problem. Verify that no plastic tubing, or other plastic components
are used in a trace gas system, including diaphragms of pressure regulators, packing of valves etc.
5. Verify the analyzer calibration using air as the span gas. Expose it to air for the minimum possible time! It
is common for span gases to be in error, and the analyzer may well be more linear than
the span gas is.
6. Flow zero gas through the analyzer for a while until the reading is stable: turn the valve to the Off
position.. Let the unit sit for four hours or so, and make sure its reading is less than 40ppm. If it is
greater than this, there is an internal leak. If so, return the unit to the factory for repair
7. Remove the cell and verify that the analyzer reads zero - 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.
