 |
|
Area-Velocity
Flowmeter Installations in Denmark
|
|
|
|
|
|
|
 |
|
Municipalities (Kommunes) throughout
Denmark Measure Sewage and Stormwater Flow with
Greyline Area-Velocity Flowmeters
Area-Velocity Flow Meters are designed to monitor flow
rates in partially filled pipes and open channels without flumes or weirs. A sealed
ultrasonic sensor is mounted on the bottom of the pipe or channel and
connected to electronics through a watertight cable. The sensor measures
both level and velocity and when calibrated with the pipe
diameter or channel dimensions, the Greyline AVFM computes
flow.
Teletronic Denmark ApS
specializes in collecting data from measurement systems, including
Greyline Area-Velocity Flow Meters, installed in sewers, channels and
streams. Instruments are powered by batteries and recharged with
photovoltaic solar panels. Measurement data is transmitted wirelessly
through GSM modems or closed UHF radio systems. Teletronic's service
includes rental, sales, installation and operation of complete
monitoring systems. Web based software allows customers the access and
monitor measurement data through the Internet. |
|
|
|
 |
|
Greyline AVFM Flowmeters and
Ultrasonic Sensors Ready for Installation
A busy day's work is ahead for
Teletronic Denmark as flowmeters and ultrasonic sensors are
set out for deployment in municipal sewer applications.
Greyline AVFM flowmeters can monitor flow in channels of
any shape but most municipal applications in Denmark are
installed in manhole pipe entries ranging in size from 150
mm to 1 m diameter (6" to 40"). |
|
|
|
 |
|
Flowmeter Electronics and Modem Repackaged in a Watertight Housing
Electronics are exposed to high humidity, condensate and rainwater in manhole installations.
Teletronic Denmark provides customers with repackaged
systems including Greyline AVFM Area-Velocity Flow Meter
electronics and Teletronic modems in sealed polycarbonate
housings. Cable entries to the electronics are made through
watertight glands so that the systems can operate reliably
and without damage in wet conditions and during periods of
accidental submersion. |
|
|
|
 |
|
AVFM Flowmeter Electronics Mounting at the Top of Manholes
Teletronic Denmark fabricates a stainless steel cross beam
which clips to the manhole frame. The Greyline AVFM
Flowmeter, battery, data logger, modem and other equipment
can be set on top of or suspended from the cross beam.
Municipal staff have easy access to electronics just
below the manhole cover and the whole assembly can be raised
and removed from the manhole to allow access to personnel. |
|
|
|
|
|
|
 |
|
Flowmeter Installations in Stainless
Steel Panels
Away from
roadways where manhole installation is unnecessary Teletronic
Denmark provides Area-Velocity flowmeter electronics in a
locked panel along with a modem and battery. A nearby
antenna transmits periodic flow readings automatically to
the municipality. The AVFM flowmeter's ultrasonic sensor is
installed in a channel below. |
|
|
|
 |
|
Submersible Ultrasonic Sensor Installed in Sewer Pipe
Using stainless steel mounting hardware Teletronic Denmark
installs a Greyline ultrasonic sensor on the invert of a
concrete pipe. Stainless steel banding is formed to the pipe
shape and screwed to the pipe. Sensor cable is tie-wrapped
to the banding and then connected to AVFM flow meter
electronics installed at the top of the access manhole. |
|
|
|
 |
|
Influent Monitoring from Two Pipes
Sewage influent to this manhole is from 100 mm (4") and
150 mm (6") pipes. The municipality of Stevns needed to
monitor flow from both sources so separate Greyline AVFM
ultrasonic sensors are installed in both pipes.
An
extension has been added to the 100 mm pipe to enable
mounting of the flow sensor. It discharges to the 150 mm
pipe below after influent to the 150 mm pipe has been
measured separately. |
|
|
|
 |
|
Stormwater Flow Monitoring
Earthen channels change shape over time due to debris, settling
and the scouring effects of high flow rates. In this
installation temporary channel walls have been installed in
a drainage ditch so that a rectangular channel shape can be
defined for flow measurement.
Greyline AVFM
flowmeter electronics and battery are protected under a temporary
rain tight cover and powered by a solar photovoltaic charging system.
After baseline flow data has been collected, the system is
removed for deployment at another location. |
|
|
|
 |
|
Problem... Sediment
Solution... Sensor Mounting
AVFM sensors should be installed at locations where flow is
calm and sediment does not form. But some stormwater
applications carry debris into sewer lines and over time the
ultrasonic sensor can become buried in sediment.
Teletronic Denmark use Greyline's AVFM "level offset"
calibration feature and raise the ultrasonic sensor above
the invert of the pipe by mounting on an adapted stainless
steel mounting bracket. Periodic flushing of the channel is
still required but by installing the sensor above the
sediment layer, the flowmeter continues to function
reliably. |
|
|
|
|
Copyright © 2012 [Greyline Instruments Inc.] All rights
reserved. Information in this document is subject to change without
notice. |