4220 Flow Meter
Section 4 Submerged Probe Installation
4-10
A variety of threaded fasteners should be available in various
overall and thread lengths; a minimum thread length of 1/4 in.
(0.63 cm) is recommended. Be sure to follow the manufacturer's
instructions carefully, and observe all safety precautions.
4.3.5 Completing the Probe
Installation
The probe installation is finished by coiling any excess sensor
cable and securing it using cable clamps or other means. The ref-
erence tube inside the cable can be restricted or blocked if the
cable is kinked, sharply bent, or otherwise pinched. The sensor
cable should be handled and mounted with care. Also, if there is
any appreciable distance between the point where the sensor
cable leaves the mounting apparatus and the location of the flow
meter, be sure to attach the cable to the flow stream wall to
prevent it from vibrating, moving around, tangling, or possibly
collecting debris.
CAUTION
Under no circumstances should you leave any extra length of
sensor cable dangling freely in the flow stream where it could
trap debris or become tangled.
Use gloves and eye protection when assembling and installing
the rings in a pipe. Though deburred, the edges of the stain-
less steel can cut if improperly handled. Please read the infor-
mation on how best to install this device.
Observe general safety procedures when entering any man-
hole. See “General Safety Procedures” in the back of the man-
ual for more information on general hazards and necessary
precautions.
Note
The countersunk holes on the base section near the mounting
tabs are for use with the four-foot probe extension (no longer
sold) only. Do not attempt to use them to mount the probe car-
riers or the probes themselves.
4.4 Other Mounting Techniques
4.4.1 Rectangular Pipes and
Channels
You can install the probe in rectangular channels by bending a
mounting ring to fit the channel. Attach the ring to the channel
wall with studs.
4.4.2 Stilling Wells or
Streams with Very Low
Velo cit y
In flow streams with a minimal flow velocity or in a stilling well,
simply attach the probe to a weighted plate and submerge the
plate in the stream or stilling well.
4.4.3 Weirs and Flumes The 4220 Flow Meter is generally used with some type of
primary measuring device, such as a weir or flume. The
placement of the submerged probe in the primary device is deter-
mined by the type of primary device. You can use one of Isco’s
mounting rings to install the probe in many weirs and flumes. If