Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 14)

<2. Instruction for Replacement of the Heater Unit>
2-5
IM 11M12A01-21E
2.1.3 Part Assembly Procedure of Sensor Assembly
(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.
F2.3E.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 2.4 Installing the Contact
(2) Next, make sure that the O-ring groove on the flange surface of the sensor (cell) is clean.
Install the metal O-ring in that O-ring groove, and then insert the sensor (cell) 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 with filter, then fully insert the U-shaped pipe and its
support into the probe.
(4) Coat the threads of the four bolts with antiseize 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 parallel
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.
Replacement of the sensor assembly is now complete. Install the detector and restart operation.
Calibrate the instrument before making a measurement.