Greyline Instruments DFS 5.1 Manuale utente
www.greyline.com
USER'S GUIDE
Installation & Operation
Instructions
Doppler Flow Switch
Model DFS 5.1
Manual Series 1.4
Note: This page has been left blank intentionally.
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DFS 5.1 Doppler Flow Switch
INDEX
INTRODUCTION ................................................................................................... 4
CONNECTIONS ..................................................................................................... 5
ADJUSTMENTS ..................................................................................................... 5
TRANSDUCER INSTALLATION ......................................................................... 8
ENCLOSURE INSTALLATION .......................................................................... 11
PRINCIPLE OF OPERATION ............................................................................. 11
APPLICATIONS BACKGROUND ...................................................................... 13
TYPICAL DFS 5.1 CONTROL APPLICATIONS ............................................... 14
APPLICATIONS HOTLINE ................................................................................. 15
PRODUCT RETURN PROCEDURE ................................................................... 15
SPECIFICATIONS ................................................................................................ 17
APPENDIX A - OPTIONS ................................................................................... 18
APPENDIX B ........................................................................................................ 20
IMPORTANT NOTE: This instrument is manufactured and calibrated to meet product specifications.
Please read this manual carefully before installation and operation. Any unauthorized repairs or
modifications may result in a suspension of the warranty.
Available in Adobe Acrobat pdf format
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DFS 5.1 Doppler Flow Switch
INTRODUCTION
DOPPLER FLOW SWITCH - Model DFS 5.1
The Greyline Doppler flow switch consists of an encapsulated ceramic transducer, a transmitter/receiver
unit, electronic circuitry to separate the Doppler frequency from the transmitted frequency and an
adjustable set-point relay. The relay also has hysterisis and delay-off capability.
The DFS 5.1 Flow Switch is housed in a watertight NEMA4X fiberglass enclosure and requires a
115VAC power supply.
Flow measurement range is 0.25 to 10 ft/second (0.076 to 3 m/sec).
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DFS 5.1 Doppler Flow Switch
CONNECTIONS:
SENSOR: Connect one sensor
coaxial cable to the Rx and GND
terminal block, and the second sensor
coaxial cable to the Tx and GND
terminal block. Tx and Rx are the
solid core of each coaxial cable, and
GND is the stranded shield of each
coaxial cable. (See page 17 for coaxial
cable preparation).
POWER INPUT: Connect 115VAC
50/60Hz to the LINE, NEUTRAL and
GROUND terminals. Do not apply
power until sensor connections have
been made.
Note
Tx = Transmitter
Rx = Receiver
Nc = Normally closed contacts
No = Normally open contacts
C = Common
ADJUSTMENTS:
Bar Graph
Display
The green LED’s indicate flow velocity. The red
LED indicates relay energized see chart for
calibration.
Relay Trip Point Insert shorting link at the flow rate indicated by
the bar graph display. A second link can be
inserted to provide a relay deadband.
Alarm State Select high flow alarm or low flow alarm by
inserting the shorting link.
Relay Drop-out
Delay
Adjust delay in 5 second increments to prevent
relay chatter on intermittent flow.
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DFS 5.1 Doppler Flow Switch
DFS 5.1 DOPPLER FLOW SWITCH CALIBRATION
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DFS 5.1 Doppler Flow Switch
DFS 5.1 DOPPLER FLOW SWITCH CALIBRATION
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DFS 5.1 Doppler Flow Switch
TRANSDUCER INSTALLATION
MOUNTING LOCATION - The position of the sensor is one of the most important considerations for
reliable flow monitoring. The same location guidelines apply to Doppler as to most other types of flow
switches.
VERTICAL OR HORIZONTAL PIPE - Vertical pipe runs
generally provide evenly distributed flow conditions. On
horizontal runs the sensor should be positioned at 3 or 9
o’clock to avoid concentrations of gas at the top of the pipe
and solids on the bottom.
Generally the sensor must be mounted away from flow disturbances such as valves, pumps, orifice
plates or venturis which tend to increase flow velocity or cause cavitation. Velocity increasing devices
often cause cavitation and erratic operation. As a guideline, mount the sensor 20 diameters upstream and
30 diameters downstream from velocity increasing devices.
Turbulence Increasing Devices: Elbows, flanged
connections and tees tend to introduce desirable
conditions of an evenly distributed flow profile with
some air or gases entrained in the flow. Sensor
mounting 6 diameters upstream and 10 diameters
downstream from these disturbances is generally
optimum.
The transducer is designed to mount longitudinally on a straight section of pipe. Do not attempt to
mount it on bends, elbows or fittings. The DFS senses flow in either direction.
Prepare an area 2 inches wide by 3 inches long for transducer bonding by removing all paint, scale and
rust. Thoroughly degrease the surface to which the transducer will be bonded. The objective of site
preparation is to eliminate any discontinuity between the transducer and the pipe wall which would
prevent acoustical coupling.
For semi permanent or temporary bonding, the following are recommended:
a) Dow Corning silicon compound #4. (Greyline Part #CC)
b) Electrocardiograph gel.
c) Petroleum gel.
The above are arranged in their order of preferred application. B & C are suggested only for room
temperature application. DO NOT USE: Silicon RTV compound (silicon rubber).
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DFS 5.1 Doppler Flow Switch
One PCK2 Pipe Clamp Kit is included with each Greyline DFS 5.1. It includes recommended silicone
coupling compound in a plastic applicator, a stainless steel sensor bracket, and a stainless strap for pipe
diameters up to 16” 406 mm. Additional pipe clamps (optional) may be attached for larger diameter
pipes.
Thread the strap through the bracket and mount loosely on the pipe ready for Sensor coupling.
SENSOR COUPLING
Prepare a pipe clamp to secure the sensor. Apply coupling compound to the coloured face of the sensor.
A bead (similar to toothpaste on a toothbrush) is ideal. Press the sensor on to the pipe and secure with
the clamp. DO NOT over tighten.
For proper operation the transducer must be fixed securely to the pipe with coupling material between
the transducer face and the pipe. Sensor installation with excessive coupling compound or use of epoxy
can result in gaps or voids in the coupling and cause errors or loss of signal. Insufficient coupling
compound will create similar conditions.
Over time temporary coupling compounds may gradually sag away from the sensor resulting in reduced
signal strength and finally complete loss of signal. Warm temperatures, water and vibration will
accelerate this process. Loss of Signal will be indicated by erratic performance of the DFS 5.1.
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DFS 5.1 Doppler Flow Switch
SENSOR COUPLING AND MOUNTING RECOMMENDATIONS
Indice
