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WATER LEVEL LOGGER INSTALLATION
On this page:
Groundwater
Surface Water
Security
Flumes and Weirs
Pipe Pressure Option
Sewer Flow Option
What to do with Extra Cable
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Groundwater Installation
Installation of a Water Level Logger in a groundwater well is very easy. For a 2" pipe, the sensor is simply inserted into the pipe. The top
of the logger rests on the top of the well pipe (see drawing at right). The logger can be concealed by a slip cap or a
locking well cap. The sensor’s measuring range should be slightly larger than the expected total
amount of change in water level (not necessarily the bottom of the well). The Water Level Logger can be adapted to larger or smaller well casings by
using standard PVC pipe reducers and fittings. The cable length is extremely difficult to increase since it has internal vent tubing. If you have
2" or larger wells, the cable may be shortened simply by coiling it around a 1" diameter stick or pipe and securing it to
the stick at both ends.
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Surface Water Installation
The best way to install the Water Level Logger in surface water is to use a 2" pipe to protect the sensor and the datalogger. You can use PVC
schedule 40, or ABS sewer drain pipe. The best protective pipe is PVC schedule 40 electrical conduit. This light grey pipe has UV protectors
and pre-formed "sweeps" or bends which enable the pipe to conform to the contours of the river bank. The sensor will slide down through 45
or 90 degree sweeps. The pipe may be buried in the river bank, secured with rocks, or fastened to the bank with large staples made by bending pieces
of concrete reinforcing steel in half and driving them into the bank. The pipe should have several large (1/2" diameter) holes drilled near the sensor
location in order to eliminate velocity effects on the sensor. Also, a smaller 1/4" hole should be drilled near the top of the pipe to allow air movement
when the water goes up and down. A standard slip cap or a locking well cap can be used to protect the
top of the datalogger. You can also adapt the pipe for a screw-on cap.
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Security
In areas where there is a problem with vandalism, a 2" galvanized pipe may be used for the entire stilling pipe. Plastic pipe, adapted to the steel pipe above water, may
be used for the underwater section. A screw-on galvanized cap can then be used to cover the datalogger. Two small pipe wrenches are required to access the datalogger,
but this installation is essentially bullet-proof and vandal-proof.
Flume and Weir Installation
For monitoring level in flumes and weirs, Global Water suggests using the standard 3' level sensor with 3' of cable. This logger/sensor combination is easily mounted and concealed
inside a section of 2" PVC pipe which can be used as its own stilling well or can be mounted in existing stilling wells.
Pipe Pressure Option Installation (Option PRP)
For Pipe Pressure applications, the sensor is housed inside a stainless steel or PVC pipe fitting with a 3/4" NPT thread on the end to be adapted to existing ball valves with
standard pipe-fittings.
Sewer Flow Option Installation (Option SWO)
The Sewer Flow Option includes a pressure sensor built into a protective mouse housing and attached to a 2” wide, 6" long stainless steel strap. When the sensor/straps
are installed at the invert of a sewer or in the pipe, the datalogger can be attached to a sewer’s stair rungs. If there is a little slack in the cable, the datalogger can be pulled out
of the manhole above the stair rungs for easy access.
When installed in a pipe that is under 12” diameter, the steel straps spring into the pipe, holding the sensor in place. Additional securement is usually not required for this simple
installation. For a sewer pipe over 12” in diameter, the sensor’s steel straps must be mounted into the pipe. The straps can be secured with molly or concrete bolts,
or with marine-grade epoxy.
To install in pipes over 12” in diameter with marine-grade epoxy, first drill 6-8 holes across the WL16-SWO's steel strap. Following the epoxy directions, pour epoxy into the sewer
pipe and place the sensor’s straps onto the epoxy. The epoxy will squeeze out of the pre-drilled holes in the strap. Spread the epoxy over the top of the steel strap. This
installation will need to set (dry and unmoved) for over 24 hours.
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What to do with Extra Cable
To shorten excess cable, coil the extra cable around a rigid, 1/2 inch diameter PVC pipe, as shown in the photographs to the right. Tape the ends of the cable onto the pipe
with electrical tape, and tape the cable onto the pipe every few inches to ensure security. About 5 feet of extra cable can be shortened into about 1 foot of coiled cable.
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