Tp 19: Double Sampling; Tp 20: Variable Sample Size - ABB PGC2000 Operation And Service Manual

14. Remove power and disconnect the cable between J9A and J9. Check continuity between J9A
terminals 1, 2, and 3 and J9 terminals 1, 2, and 3, respectively. If any wires are open replace the
cable, apply power and repeat step 11.
15. Apply power to analyzer and switch DC solenoid driver using procedure in step 7.
16. If voltage does not switch, replace DC solenoid valve driver PCB.
17. If voltage does not switch, replace Chroma I/O board.
18. Close and tighten the Controller front door.
19. Apply purge air and power.
20. Allow temperature to equilibrate.
21. Perform an analysis to verify analyzer operation.

TP 19: DOUBLE SAMPLING

1. Request an analysis run on stream 10 (calibration).
2. Verify double apex peaks by analyzing calibration standard of individually resolved peaks.
3. When the analysis begins, stop the analysis at the end of the cycle.
4. Schedule Sample Valve Off at cycle time plus 20 seconds.
5. Run a second analysis. When the second analysis begins, stop analysis at the end of the cycle.
If valve is double sampling, the peak shape will now be normal in most cases.
6. Schedule valve off at normal cycle time.
7. Manually switch the Sample Valve Off and observe the chromatogram. A second set of peaks
may now appear. (This is another indication of double sampling.)
8. Turn off power, carrier, and sample supply to the analyzer.
9. Replace sample valve seals and stem (see "SAMPLE VALVE REPAIR" in Section 8).
10. Restore carrier, sample, and power.
11. Request calibration analysis to verify problem is solved.

TP 20: VARIABLE SAMPLE SIZE

1. For a liquid sample valve, observe the analyzer effluent sample flow rotometer for the presence of
bubbles. The sample pressure and temperature must be such that the sample pressure at the
sample valve is 25 psig above the bubble point of the sample.
2. Ensure that the sample pressure at the sample valve is above the bubble point of the sample.
3. A booster pump may be necessary for process sample if the supply pressure is below the bubble
point of the sample or the sample flow rate is not adequate at the supply pressure.
7-10 2000-OSM, F1