Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 10)

<2. Instruction for Replacement of the Heater Unit>
2-1
IM 11M12A01-21E
2. Instruction for Replacement of the
Heater Unit
2.1 Instruction for Replacement of Model ZR22A
Heater Unit
CAUTION
• Allow adequate time for the sensor (cell) and heater assembly to cool before replacing them, or
you may get burnt.
• When removing the cell, the metal O-ring should be replaced with a new one. Never reuse a
metal O-ring. Once-used metal O-ring should be replaced with a new one.
• The grease used for rubber O-rings lubricant see ⑭ , ㉑ , ㉒ etc. in Figure 2.2, 2.3 makes
poisonous gas when heated to more than 250ºC. Wash your hands thoroughly after work!
Especially be careful if you smoke.
2.1.1 Removal Procedures for Sensor Assembly
(1) Remove the four bolts and associated washers from the tip of the detector probe.
(2) Remove the U-shaped pipe support together with the U-shaped pipe. Remove filter also.
(3) Pull the sensor assembly toward you while turning it clockwise. Also, remove the metal O-ring
between the sensor assembly and the probe. When replacing the sensor assembly, be careful
not to scratch or dent the tip of the probe with which the metal O-ring comes in contact (the
surface with which the sensor flange also comes in contact). Otherwise, the measurement gas
will not be sealed.
(4) Use tweezers to pull the contact out of the groove in the tip of the probe.
(5) Clean the sensor assembly, especially the metal O-ring contact surface to remove any
contaminants adhering to that part. If you can use any of the parts from among those removed,
also clean them up to remove any contaminants adhering to them.
Once the metal O-ring has been used, it cannot be reused. So, be sure to replace it.
F2.1E.ai
Dust filter
(optional) Bolts (four)
Washers
(four)
Sensor (cell)
U-shaped pipe
Metal O-ring
Contact
Probe
1/8 turn – tighten bolts 1/8 turn
(approximately 45°) each
U-shaped pipe
support
Screw
Filter
Figure 2.1 Exploded View of Sensor Assembly