Model 200AU-NOy Option Manual Addendum
The external sample pump is capable of maintaining the cell pressure at less than 3.0 "Hg-A. If a
higher pressure is noted, the pump may need servicing. Check the pump and pneumatic system
for leaks or rebuild pump. The ozone scrubber is integrated into the converter case inside the
instrument.
See Figure 1.1 for component locations.
The heater, thermocouple, and converter assembly is designed to be replaced as a single unit.
Check Figure 5.2 for component location.
1. Turn off the power to the M501Y at the chassis front panel
2. Allow the converter to cool.
CAUTION!
The converter operates at 315°C. Severe burns can result if
not enough time is allowed for the assembly to cool. Do not
handle assembly until it is at room temperature.
3. Disconnect the gas fittings and power cable from the can.
4. Remove the entire assembly from the NEMA chassis.
A. Remove the pneumatic fittings.
B. Remove the converter assembly from the chassis by loosening the 4 captive
screws that secures the assembly to the chassis.
5. Remove bottom bracket and re-attach it to the replacement converter assembly.
6. Install the assembly back into the analyzer.
7. Re-attach the electrical and pneumatic fittings. Leak check the assembly when
completed. 8. Turn the power back on. The insulation can emit a burnt odor for the first 24
hours, this is normal. Allow the converter to burn-in for 24 hours, then re-calibrate the
instrument.
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