Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 146)

IM 11M13A01-04E 11-4
(6) 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 tightened, it can no longer be used. So, be sure to
replace it.)
3. Part assembly procedure
(1) First, install the contact. Being careful not to cause irregularities in the pitch of the
coil spirals (i.e., not to bend the coil out of shape), place it in the ringed groove
properly so that it forms a solid contact.
Groove in which the contact
(E7042BS) is placed
F11.2E.EPS
Figure 11.2 Installing the Contact
(2) Next, make sure that the O-ring groove on the flange surface of the sensor is clean.
Install the metal O-ring in that O-ring groove, and then insert the sensor in the probe
while turning it clockwise. After inserting it until the metal O-ring comes in contact
with the probe’s O-ring contact surface, properly align the U-shaped-pipe insertion
holes with the bolt openings.
(3) Attach the U-shaped pipe to its support, then fully insert the U-shaped pipe, filer and
its support into the probe.
(4) Coat the threads of the four bolts with anti-seize grease and then screw them in
along with the washers. First, tighten the four bolts uniformly by hand, and then use
a torque wrench to tighten all areas of the metal O-ring uniformly, that is, to make
sure the sensor flange is perfectly horizontal to the O-ring’s working face in the
probe. This is done by tightening first one bolt and then its opposing bolt each 1/8
turn, and then one of the other bolts followed by its opposing bolt, each also 1/8
turn.
This continues in rotating fashion until they are all fully tightened with the torque
wrench preset to approximately 5.9 N•m. If they are not uniformly tightened, the
sensor or heater may be damaged. Check with light that there is no gap between
sensor flange and probe.
Replacement of the sensor assembly is now complete. Attach and fix the Flame
Arrestor Assembly. Install the detector and restart operation. Calibrate the instrument
before making a measurement.