Campbell Scientific Sentek TriSCAN® Manual v 1.2a - Manual (Page 37)

TriSCAN Manual Version 1.2a
Copyright © 1991 – 2004 Sentek Pty Ltd All rights reserved Page 30
Installing the Top Cap
The top cap assembly is installed after the access tube has been cleaned and the bottom stopper fitted. To
install the top cap assembly follow these steps:
1. Ensure the 4 cm of access tube protruding from the soil is clean on the inside and the outside.
2. With a silicone gun and new nozzle, apply three rings of silicone around the outside of the access
tube about 1 cm below the top rim of the tube.
3. Unscrew the cap from the top cap assembly base.
4. Take the top cap base and push it onto the top of the access tube with a slight forward and
backward rotating motion until the base of the top cap touches the undisturbed soil surface.
5. Wipe off excess silicone from the inside of the access tube.
6. Screw the top cap back on the top cap housing.
Installing the probe
Now the probe is ready for insertion into the access tube. To insert and connect the probe, follow these
steps:
1. Pass the cable through the cable gland and into the centre of the top cap assembly.
2. Strip back the outer sheath of the cable so that 200 mm of inner cable are exposed.
3. Strip back the inner cables to expose 5 mm of bare copper conductor.
4. Unplug the green connector from the top of the probe, and screw the wires into the connector plug.
Follow the wiring diagram supplied with the probe interface manual. Check that the connector is
crimping the copper wire strands and not the plastic sheath of the cable. Also ensure that copper
wire does not protrude from the connector.
5. Pull the cable back through the cable gland until the black outer sheath just protrudes from the cable
gland into the top cap assembly.
6. Inject a small quantity of silicone into the centre of the cable at the end of the outer sheath and
around the wires. This will prevent any moisture from moving into the top cap assembly via the
cable.
7. Align the probe handle with lugs on the top cap and carefully slide the probe into the access tube
until the handle rests neatly on the top cap.
8. Plug the green connector into the top of the probe.
9. Place a silica gel bag on top of the probe under the arch of the handle.
10. Ensure that there is no dirt on the O-ring and that it is seated properly in the top cap.
11. Screw the top of the top cap assembly onto the top cap and firmly tighten by hand.
12. Tighten the cable gland.
13. The probe can now be connected to the logger. Refer to the logger user manual for instructions on
connecting to the logger.