Cpu - Teledyne T200 User Manual

S P
AMPLE RESSURE
1. Measure the pressure on the inlet side of S1 with an external pressure
2. Measure the voltage across TP4 and TP1.
Expected mVDC
EXAMPLE: If the measured pressure is 20 Hg-in-A, the expected voltage level between
TP4 and TP1 would be between 2870 mVDC and 3510 mVDC.
EXAMPLE: If the measured pressure is 25 Hg-in-A, the expected voltage level between
TP4 and TP1 would be between 3533 mVDC and 4318 mVDC.
• If this voltage is out of range, then either pressure transducer S1 is bad, the board
is bad or there is a pneumatic failure preventing the pressure transducer from
sensing the absorption cell pressure properly. Replace the PCA.
V P
ACUUM
Measure the pressure on the inlet side of S2 with an external pressure meter.
Measure the voltage across TP5 and TP1.
Evaluate the reading in the same manner as for the sample pressure sensor.
O F S
LOW
3
• Measure the voltage across TP3 and TP1.
• With proper flow (80 cc
approximately 2V ± 0.25 (this voltage will vary with altitude).
• With flow stopped (photometer inlet disconnected or pump turned OFF) the
voltage should be approximately 1V.
• If the voltage is incorrect, the flow sensor S3 is bad, or the board is bad (replace
the PCA) or there is a leak upstream of the sensor.

CPU

There are two major types of CPU board failures, a complete failure and a failure associated
with the Disk on Module (DOM). If either of these failures (described next) occurs, contact
the factory.
For a complete failure, assuming that the power supplies are operating properly and the
wiring is intact, the CPU is faulty if on power-on, the watchdog LED on the motherboard
is not flashing.
• In some rare circumstances, this failure may be caused by a bad IC on the
motherboard, specifically U57, the large 44 pin device on the lower right hand side of
the board. If this is true, removing U57 from its socket will allow the instrument to start
up but the measurements will be invalid.
083730200A DCN7962
S C
ENSOR HECK
meter.
• The expected value for this signal should be:
(
Pressure
=
30.0
Hg-In-A
S C
RESSURE ENSOR HECK
C
ENSOR HECK
/min through the O
3
Teledyne API T200 NO/NO
)
x +
4660 250
mvDC mvDC
generator), this should be
3
/NO Analyzer with NumaView™ Software
2 x
± 10%
rdg
157