Teledyne 6200E - Sulfides Analyzer - Manual (Page 260)

TROUBLESHOOTING & REPAIR Model 6200E Instruction Manual
260 M6200E Rev: A1
11.5.14. High Voltage Power Supply
The HVPS is located in the interior of the sensor module and is plugged into the PMT tube (Figure
10-13). It requires 2 voltage inputs. The first is +15 which powers the supply. The second is the
programming voltage which is generated on the Preamp Board. This power supply is unlike a
traditional PMT HVPS. It is like having 10 independent power supplies, one to each pin of the PMT.
The test procedure below allows you to test each supply.
Adjustment of the HVPS is covered in the factory calibration procedure in Section 11.6.3.
11.5.15. Pneumatic Sensor Assembly
The pressure/flow sensor circuit board, located behind the sensor assembly, can be checked with
a voltmeter using the following procedure, which assumes that the wiring is intact and that the
motherboard and the power supplies are operating properly.
Measure the voltage across TP1 and TP2, it should be 10.0 ± 0.25 V. If not, the board is faulty.
Measure the voltage across capacitor C2, it should be 5.0 ± 0.25 V. If not, the board may be
faulty.
11.5.15.1. Sample Pressure
Measure the voltage across test points TP1 and TP4. With the sample pump disconnected or
turned off, this voltage should be 4500 ± 250 mV. With the pump running, it should be about 0.2
V less as the sample pressure drops by about 1 in-Hg-A from ambient pressure. If this voltage is
significantly different, the pressure transducer S2 or the board may be faulty. A leak in the sample
system to vacuum may also cause this voltage to be between about 0.6 and 4.5. Make sure that
the front panel reading of the sample pressure is at about 1 in-Hg-A less than ambient pressure.
11.5.16. IZS Option
The zero/span valves and IZS options need to be enabled in the software (contact the factory on
how to do this). See Figure 5-2 and 5-3 for a flow diagram with zero/span valve or IZS option.
• Check for the physical presence of the valves or the IZS option.
• Check that a working perm-tube is installed in the IZS oven assembly.
• Check front panel for correct software configuration. When the instrument is in SAMPLE
mode, the front panel display should show CALS and CALZ buttons in the second line of
the display. The presence of the buttons indicates that the option has been enabled in
software. In addition, the IZS option is enabled if the TEST functions show a parameter
named IZS TEMP.
The semi-permeable PTFE membrane of the permeation tube is affected by humidity. If the
instrument is installed in an air-conditioned shelter, the air is usually dry enough to produce good
results. If the instrument is installed in an environment with variable or high humidity, variations
in the permeation tube output will be significant. In this case, a dryer for the supply air is
recommended (dew point should be-20° C or less).
The IZS option is heated with a proportional heater circuit and the temperature is maintained at
50° C ±1°. Check the IZS TEMP function via front panel display (Section 6.2.1) and the