Valmet Valmet MCA, Installation & Owner'S Manual, Page: 46 / 66

11.2. Antenna cables, Fork Sensor
NOTE: Before removing the sensor, check that the pro-
cess pipe is unpressurized and empty and that it is safe
to remove the sensor.
Removal: (Fig. 2 and 3)
1. Place the body of the sensor into a table vice such
that the sensor head is on top. Use aluminum
buffers in the between the vice jaws and the
sensor.
2. Remove the sensor electronics according to
chapter 11.1.
3. Lift the Pt-100 cable from the tape on the base
plate.
4. Remove the uppermost mounting screw on the
probe antenna side. Screw in a longer screw in its
place, e.g. M6x50 is a suitable size. This screw
will serve to hold the sensor in place when the
base plate is removed.
5. Remove the five other base plate mounting screws.
6. Pull the base plate 10mm away from the sensor
body.
7. Disconnect the antenna cable from the base plate
by holding the connector in place with an 8mm
wrench (e.g. SMA wrench) while you use a 10 mm
socket key to open the lock bushing that is at-
tached to a connector on the electronics side of
the base plate.
NOTE: Don't allow the connector body to rotate while
you turn the lock bushing.
8. Remove the long steering screw and the base
plate from the sensor body. At the same time,
guide the Pt- 100 cable through the base plate.
9. Remove the cable of the flush-mounted antenna
with an SMA wrench.
10. Remove the cable support bushing by pulling it
through the feed-through hole with drawing pliers.
11. Open the Pt-100 coupling on the outer edge of the
sensor shaft with plug spanner OUL00323. Check
that the cable also rotates during removal.
12. Pull the Pt-100 sensor about 100mm outwards and
let it hang by its cables.
13. Remove the MCX connector from the probe an-
tenna by prying with pointed pliers. Push the Pt-
100 cable to the side so that the connector is able
to be removed.
14. Pull the microwave cable carefully out through the
feed-through hole on the shaft toward the flush-
mounted antenna.
Connecting:
1. Install the probe antenna's microwave cable into
the MCX connector: Push the cable end with the
straight angle connector through the shaft such
that the connector is just oppisite the probe an-
tenna connector. Connect the connector to the end
hole by prying with a 4mm screwdriver. Handle
the cable with care, so that it stays in shape and
eases future installation.
2. Install the flush-mounted antenna's cable into the
SMA connector: Put the connector that is to be
installed in the base plate on the side of the sensor
body opposite the previous cable. Tighten the SMA
connector with a torque wrench to 1 Nm torque.
Handle the cable with care, so that it stays in
shape and eases future installation.
3. Install the thermoelement on the sensor body:
Check that the O-ring is in the sealing groove.
Remove the old teflon tape from the thread and
put two new layers of teflon tape in its place. Check
that the tape does not cover the O-ring. Take care
that the cable also rotates . Tighten it with plug
spanner OUL00323 to 12 Nm torque.
4. Set the cable support bushing into place and put
a drop of super glue on the side of the bushing
before attaching it. The antenna cable should be
in the upper groove, and the Pt-100 sensor cable
should be in the lower groove.
Installation & Owner’s manual OUL00298 V2.3 EN 46 Valmet Mircowave Consistency Transmitter