Pmt Temperature Control Pca; O 3 Generator - Teledyne T200 User Manual

PMT TEMPERATURE CONTROL PCA

The temperature control PCA is located on the sensor housing assembly, under the slanted
shroud, next to the cooling fins and directly above the cooling fan.
If the red LED located on the top edge of this assembly is not glowing the control circuit
is not receiving power. Check the analyzer's power supply, the relay board's power
distribution circuitry and the wiring connecting them to the PMT temperature control PCA.
TEC C
ONTROL
Four test points are also located at the top of this assembly and they are numbered left to
right, starting with the T1 point immediately to the right of the power status LED. These
test points provide information regarding the functioning of the control circuit.
• To determine the current running through the control circuit, measure the voltage
between T1 and T2. Multiply that voltage by 10.
• To determine the drive voltage being supplied by the control circuit to the TEC,
measure the voltage between T2 and T3.
• If this voltage is zero, the TEC circuitry is most likely open.
or,
If the voltage between T2 and T3 = 0 VDC and the voltage measured between
•
T1 and T2 is 0 VDC, there is most likely an open circuit or failed op amp on
control PCA itself.
• If the voltage between T2 and T3 is 0 VDC and the voltage measured between
T1 to T2 is some voltage other than 0 VDC, the TEC is most likely shorted.
• T4 is tied directly to ground. To determine the absolute voltage on any one of the other
test points make a measurement between that test point and T4.
O GENERATOR
3
The ozone generator can fail in two ways, electronically (printed circuit board) and
functionally (internal generator components). Assuming that air is supplied properly to the
generator, the generator should automatically turn on 30 minutes after the instrument is
powered up or if the instrument is still warm. See Section 6.2.3 for ozone generator
functionality. Accurate performance of the generator can only be determined with an ozone
analyzer connected to the outlet of the generator. However, if the generator appears to be
working properly but the sensitivity or calibration of the instrument is reduced, suspect a
leak in the ozone generator supply air.
A leak in the dryer or between the dryer and the generator can reduce sensitivity and cause
performance drift. Carry out a leak check (Section 5.6.11).
083730200A DCN7962
T P
EST OINTS
Teledyne API T200 NO/NO /NO Analyzer with NumaView™ Software
2 x
163