FujiFilm ZPA, Service Manual

Page: 21 / 45

TN5A1191-E
13
2.4 Detector unit (excluding O
2
sensor)
z
Recommended replacement cycle:
5 years
z
Possible troubles occur on this part:
a) Degraded sensitivity due to filler gas leakage
Symptoms: calibration error, large fluctuation of the reading
Check: Access Maintenance Mode > Sensor Input Value. Check the count for
each component. If the light source works properly and the cell is not
contaminated, the count during zero gas flow should be between
35,000 and 80,000 (ZPA) or between 350,000 and 800,000 (ZPB and
ZPG). If the count is lower than 30,000 (ZPA) or 300,000 (ZPB and
ZPG), the sensitivity of the analyzer may be degraded.
b) Damage of the mass flow sensor
Symptoms: display of dashes (----), Error 1
Check:
1. Turn off the analyzer.
2. Disconnect the connector on the detector unit.
3. Measure the resistance J1–J4 and the resistance J2–J3 of the amp board on the detector unit.
The resistances shall be between 57 ohm and 63 ohm. If the resistance is greater than the above range, it
means the sensor element is damaged.
Do not use an ohmmeter through which an electric current of 2 mA or greater passes. The element may
be damaged.
c) Detector voltage control error
Symptoms: calibration error, large fluctuation of the reading
Check: Measure the voltage between the terminals DV1 and GND on the
AMP board.
The following table shows the allowable voltages for each
detector.
Check terminal Check voltage Detector type(*1)
DV1-GND
(detector
voltage)
+6.5±0.05 V
CO-L, CO-M (for ZPA &
ZPB), CO-F, CO-H
CO
2
-L, CO
2
-M, CO
2
-H
+8.08±0.1 V CH
4
-L, C H
4
-M, C H
4
-H
+12±0.1 V NO-H, CO-M (for ZPG)
+9.05±0.1 V SO
2
-BH
*1: The type of detector is indicated on the label on the detector.
Detector
Label
CO-L
Type