3 replacement of the heater unit, Replacement of the heater unit -4 – Yokogawa Integral Oxygen Analyzer ZR202 User Manual
Page 164

<11. Inspection and Maintenance>
11-4
IM 11M12A01-02E
F11.3E.ai
Dust filter
(optional)
Bolts (four)
Washers
(four)
Sensor
U-shaped pipe
Filter
Metal O-ring
Contact
Probe
1/8 turn – tighten bolts 1/8 turn
(approximately 45°) each
U-shaped pipe
support
Screw
Figure 11.3 Exploded View of Sensor Assembly
NOTE
Optional Inconel bolts have a high coefficient of expansion. If excess torque is applied while the
bolts are being tightened, abnormal strain or bolt breakage may result.
So, tighten the bolts following the instructions given above.
11.1.3 Replacement of the Heater Unit
This section describes the replacement procedure for the heater unit.
The sensor or ceramic heater-furnace core internal structure is subject to fracturing, so do NOT
subject it to strong vibrations or shock. Additionally, the heater unit reaches high temperatures
and is subjected to high voltages. So, maintenance services should be performed after the power
is off and the heater unit temperature has returned to normal room temperature.
For details, refer to IM11M12A01-21E “ Heater Assembly “.
NOTE
If the heater strut assembly can not be removed because a screw has fused to its thread,
one of our service representatives can fix it.
8th Edition : Jan.13,2012-00