FujiFilm ZPA, Service Manual

Page: 23 / 45

TN5A1191-E
15
2.6 Built-in O
2
sensor (galvanic type)
z
Recommended replacement cycle:
2 years
z
Possible troubles occur on this part:
Sensor deterioration
Symptoms: span drift or unstable readings
Check: Disconnect the cable from CN16 on the main board. Connect a digital voltmeter on the both ends of
the connector of the O
2
sensor side. If the voltage while flowing the atmospheric air is 10 mV or
less, the sensor needs to be replaced.
z
Replacement:
Refer to the instruction manual. Carry out the zero and span calibration for O
2
sensor.
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Sensor life:
The sensor deteriorates with age, regardless if it is used or not. The sensor can be used until the output
under the atmospheric air of normal temperature and pressure becomes less than 70% of the initial value.
The design life of the sensor is expressed as multiplication of the O
2
concentration (vol%) and the time (h).
Where: temperature: 20°C, humidity: 60 vol%RH, atmospheric pressure: 1013 hPa
Theoretically estimated replacement cycle of the galvanic O
2
sensor (KE-25) used in this gas analyzer is
450,000 vol%h. Based on this estimate, if you continuously measure the oxygen of 25 vol%, the
replacement cycle should be:
450,000 vol%h ÷ 25 vol% ÷ 24 h/day ÷ 365 days/year
§
2.05 year
2.7 PCB
* Refer to Appendix 3: PCB component layout.
1) Main board
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Voltage check
Check terminal Check voltage Contents
TPVC1-TPVS1 +5
r
0.3 V Digital 5 V
TP15-TPG1
+15
r
0.5 V
Analog 15 V
TPN15-TPG1
–15
r
0.5 V
Analog –15 V
TPVH1-TPVS1
+3.3
r
0.2 V
Digital 3.3 V
TPVL1-TPVS1 +1.25
r
0.1 V Digital 1.25V
Notes
x
The main board is programmed according to the ordered specification. When you order the replacement
PCB, provide the serial number of the analyzer so that you can get the one properly programmed.
x
Turn off the analyzer before replacement. Otherwise, the electronic components may get damaged.
z
After replacement:
1. Carry out the voltage check as shown above.
2. Adjust the contrast of the display.
Menu mode > Parameters > Contrast
Refer to the instruction manual for the detail.
3. Check if all the keys work properly.