UNIDATA
Unidata Manual 6293 - Precision Water Level Instruments Issue 2.1
22
5 SITE INSTALLATION
The site should be constructed according to the instructions in the relevant
appendices.
Installation of the instrument at your measuring location is a simple process if
the system has already been prepared and bench tested. It generally involves the
following steps:
•
Installing the instrument onto the prepared floatwell.
•
Installing the float system.
•
Setting the water level display.
•
Mounting and cabling.
5.1 Installing the Instrument in the Recording Position
The Water Level Instrument should be installed on a shelf or bracket suitably
positioned over a bore or stilling well. The face of the pulley must be vertical
otherwise the float line may be dislodged as the pulley rotates.
It is designed to connect to a Logger via a 4-wire cable less than 5 metres long
(see note in connection details for cable lengths up to 10 metres). The cable is
fed into the instrument through a cable gland in the base.
The Water Level Instrument should be protected from direct weather by a
shelter. It is not waterproof.
5.2 Installing the Float System
A float system consists of a float, with a floatline and counterweight. This
system has to be installed so it turns the float pulley while the float moves
through the complete range of water level measurements required.
To install the float system, do the following:
1. Select a float line of sufficient length. Handle it carefully as any kinks,
particularly in a beaded float line, may cause failures.
2. Attach the counterweight using the swages supplied to crimp a secure loop
through the counterweight eye.
3. Lower the counterweight into the well until it touches the well bottom or is
below the minimum level to be measured.
4 Pass the float line over the float pulley of the instrument and back below the
instrument bracket, to a point above the maximum level to be measured.
5. Cut the float line to this length and form a loop through the float eye.
6. Lower the float, rest it on the water surface and let it float free.
7. Position the floatline in the groove of the float pulley. If you use beaded
