Table of Contents
Advertisement
4.0 MAINTENANCE
4.1 SO2 Analyzer Maintenance
Maintenance of the SO2 analyzer is covered in Section 8 of the 6200A manual.
4.2 Changing the Quartz Tube
1. Turn off M501TRS and allow it to cool to room temperature.
2. See Figure 2.4. – M501TRS Layout
3. Remove the screws from the top inside of the front panel and fold panel downward.
4. Loosen front and rear fittings at each end of the tube.
5. Carefully slide tube out of heater – the ceramic bushings at each end of the heater are very fragile.
6. Slide in new tube and re-connect fittings.
7. Leak check the unit.
8. Check the converter efficiency. See Section 4.3
4.3 Checking the Converter Efficiency
After maintenance it is good practice to check the converter efficiency. To check the converter efficiency,
perform the following procedure:
1. Obtain a gas blender that will create H2S span gas (either permeation tube or tank) with CO2 gas as
the diluent. Remember that rotameters and mass flow controllers are calibrated with air or nitrogen.
Using them with CO2 will produce large calibration errors. Since CO2 gas has considerably different
characteristics, use flowmeters such as soap bubble, or BIOS – DryCal flowmeters that measure
volume flow.
2. Produce a calibration gas of 400 ppb H2S at a flow greater than the demand of the instrument, vent the
excess gas out of the room.
3. Allow the 6200A to stabilize at span.
4. Adjust the converter efficiency by:
Lower the set-point temperature of the Converter in 5
minutes minimum between increments until a drop of approximately 1% Full Scale is
observed. Note the Thermal Converter temperature.
Increase the set-point temperature in 5C increments allowing 10 minutes minimum
between increments until a drop of approximately 1% Full Scale is observed. Note the
Thermal Converter temperature.
Set the set-point value to fall midway between the low and high temperatures.
TAI - Thermal Converter Operator Manual - Page 19
o
C increments allowing 10
Advertisement
Chapters
Table of Contents
Troubleshooting
