Compu-Flow C6 User manual

Compu-Flow™ Doppler
™
Compu-Flow™ Doppler Ultrasonic Flow Meter
Compu-Flow
C6 Quick Start Guide
www.advancedflow.com
1-800-649-5331

INTRODUCTION:
Compu-Flow™ Doppler
When you need a reliable flow meter the Compu-Flow™ is the ri ht choice. We have been
manufacturin for the flow meter markets for the last 35 years.
The Compu-Flow™ Doppler ultrasonic flow meter provides an accurate and easy-to-use
measurin system for hi h-solid fluid flow throu h pipes 1.00 inch to 999 inches (inside
diameter). The Doppler flow meter is well suited for flow measurement applications such
as slud es, slurries, aerated liquids, sewa e, dred es, pulp, plastics, and activated slud es.
C6 Quick Start Guide
The Doppler flow meter features clamp-on transducers and a ru ed NEMA 4X enclosure,
and is a lon -term, maintenance-free solution for your hi h-solid flow measurement
requirements. Enclosure IP65, Sensor IP68.
2

INTRODUCTION:
Compu-Flow™ Doppler
Components of the Compu-Flow™
Doppler Ultrasonic Flow Meter System
A typical Doppler flow meter system is
comprised of an electronics enclosure, with a
display panel, and two clamp-on transducers.
The Doppler flow meter is confi ured with clamp-on transducers. When installed,
the sensors ather fluid flow data throu h a pipe and send this information to the
system electronics. The electronics then convert, transmit, and display the received
data
.
ELECTRONICS ENCLOSURE AND DISPLAY PANEL
The display panel in the electronics enclosure
TRANSDUCTORS AND CABLING
features an easy-to-read LCD screen, a keypad, and LEDs to interface with the flow
meter. The Doppler flow meter can be wall mounted for permanent installation or a
portable option is also available.
data
.
The clamp-on transducers allow you to install the Doppler flow meter without
shuttin down flow and are ideal for smooth, clean pipe walls. The transducers are
NEMA 6-rated and fully submersible. Contact “Compu-Flow Systems Support” for
information on confi urin your meter for continuous submersion.
3
THEORY OF OPERATION
The Compu-Flow™ Doppler ultrasonic flow meter measures flow velocity by
sensin si nals from reflective materials within a liquid and measurin the
frequency shift due to the motion of these reflective materials. The Doppler effect
states that the received frequency is a function of the transmitted frequency and
the relative motion between transmitter and the receiver. The clamp-on
transducers allow you to install the Doppler flow meter without shuttin down flow
and are ideal for smooth, clean pipe walls. The transducers are NEMA 6-rated and
fully submersible.
The classic example of the Doppler effect is the train whistle increasin in pitch to
the listener at the station as the train approaches, then decreasin in pitch as the
train moves away from the station. To the person ridin on the train, the pitch
remains the same.

INTRODUCTION:
Compu-Flow™ Doppler
The increasin pitch is due to phase-front compression and the decreasin pitch is
due to phase-front expansion. The Doppler flow meter uses this effect to measure
the velocity of a liquid throu h a pipe wall.
Sonic Reflectors
The Doppler flow meter requires sonic reflectors in order to operate. These
reflectors may consist of particles or air bubbles within the flow to be measured.
Your readin s may vary sli htly with chan es in concentration or size of these
reflectors as well as the pipe condition and size.
Note: Glycerin is the only known industrial liquid today that is not sonically
conductive.
The Doppler flow meter uses two similar transducers to sense flow in a pipe. These
transducers are mounted on the outside of a pipe. This confi uration presents no
obstruction to flow, and will not cause associated pressure drops.
Accuracy
The
Doppler
flow
meter
output
si nal
is
linear
(as
opposed
to
square
root),
which
4
The
Doppler
flow
meter
output
si nal
is
linear
(as
opposed
to
square
root),
which
means that accuracy is not a function of flow rate. Within certain application limits,
the meter is ideal because it is not affected by chan es of pressure within the
process nor by chan es of viscosity, temperature, specific ravity, sound velocity, or
electrical conductivity.
Summary
The Doppler flow meter is a non-intrusive flow meter system which operates by
sensin the frequency shifts of si nals reflected from particles, air bubbles, or
density differences within a liquid, producin a linear si nal proportional to the
flow of the liquid within the pipe.
• No pipe section is required to install the meter.
• The meter is not affected by chan es in temperature, viscosity, specific ravity, or
the speed of sound within the liquid.
• The liquid does not have to be electronically conductive.
• A minimum particle concentration of 35 ppm @ 40 micron of suspended solids or
air bubbles is required.
• The reflector must have at least a 0.2% density difference than the liquid
medium.
• For accurate volumetric measurement the pipe must be full at all times.
• The transducers are normally coupled to the outer pipe wall with reaser, sonic
el or epoxy.

INTRODUCTION:
Compu-Flow™ Doppler
• In order to obtain accurate measurements adequate upstream and downstream
pipe runs are required. Recommended strai ht-run requirements from any
disturbance of flow are 10 diameters upstream and 20 diameters downstream.
Assessin Particles or Air Bubbles
The ultrasonic beam from the transducer is transmitted throu h the pipe wall into
the liquid. The particles, air bubbles suspended in the liquid, have to be lar e
enou h to act as reflectors to return the si nal back to the transducer so that a
measurement may be taken. It is important to understand that the ultrasonic beam
from the Doppler flow meter does not penetrate air very well. A few bubbles will
not affect flow meter performance, but too many bubbles may cause the meter to
malfunction.
The flow to be measured must always have a sufficient number of sonic reflectors
of ample size in order to provide reflection of the transmitted sound. If the
reflectors do not have sufficient density difference they will neither rise nor fall in
the solution but remain suspended. The specific ravity will also affect the ability of
a particle to reflect sound. A ood example of a reflector is a sand particle or an air
bubble. A poor example is al ae or onion skins.
Note
:
At
a
frequency
of
rou hly
650
kHz,
the
minimum
particle
which
can
be
5
Note
:
At
a
frequency
of
rou hly
650
kHz,
the
minimum
particle
which
can
be
sensed is 40 microns @ 35 parts per million (ppm) and at least 0.2% density
difference from the liquid.
Assessin Pipe Material and Condition
Doppler flow meter performance is best maximized by usin pipin that is sonically
conductive. The Doppler flow meter assumes that the path by which the ultrasonic
beam enters the pipe and returns to the transducer is ultrasonically homo enous,
which means that you must use your flow meter with pipes with non-porous
smooth pipe walls. Concrete-lined pipes, old or crystallized cast iron pipes, hand-
wrapped fiber lass pipe, and old pipin with air inclusions do not exhibit the
required homo eneity. Avoid usin the Doppler flow meter for flow measurement
on these pipes unless proper operation is proven by the manufacturer throu h
demonstration.
Contact “Compu-Flow Systems Support” for more information on an alternate
meter if your application is not suitable for the Doppler flow meter.

Compu-Flow™ Doppler
INSTALLATION:
Pipe Vibration
Moderate pipe vibration does not usually adversely affect the Doppler flow meter,
since the vibration of the pipin is at a si nificantly lower frequency than the
ultrasonic beam used to measure flow. However, in situations where the transducer
si nal stren th is low because of fluid, pipin , or other environmental factors,
measurement accuracy may be further decreased by pipe vibration. In these
situations your display panel may re ister flow when there is none due to the
vibration. If you can not bracket the pipe to reduce vibration, you may be able to
rectify the problem by relocatin the transducer to a pipe location with less
vibration.
Assessin Flow Profile
STRAIGHT RUN REQUIREMENTS
As with other flow meters such as vortex or ma netic flow meters, the Doppler
flow meter needs a well-developed flow profile to ensure accurate flow
measurement. To assure a well-developed profile, choose a measurement point on
a lon run of pipe well away from elbows, valves, pumps, flan es, and other
possible
sources
of
turbulence
.
NO
NO
Air could be trapped
Pipe must be full
Down flows
must have
back pressure
>= 10Ø >= 5Ø
Fig. 1. Best recommended ) spots to install
flow meters:
6
possible
sources
of
turbulence
.
The ideal placement of the Doppler flow meter is with 20 diameters of strai ht run
upstream and 10 diameters of strai ht run downstream between the transducers
and any disturbance of the flow. Most typical flow meter applications use 10
diameters of strai ht run upstream and 5 diameters downstream from any
disturbance of the flow.

INSTALLATION:
Compu-Flow™ Doppler
However, when the measured fluid is too clean to provide the proper number of
reflective particles, one may position the transducer near the pump or source of
turbulence in such a manner as to obtain stable readin s in a continuous flow full
pipe situation. Usin a transit time meter may be another viable option if the
Doppler flow meter is not performin ideally. A point to remember is that
turbulence is a non-linear function of flow, so turbulence can create reflected
si nals. Interpret readin s near turbulent flows with caution.
Sources of turbulence are elbows, flan es, valves, orifices, wed es, pumps, pipe
openin s, and pipe irre ularities (rust, corrosion, and buildup). Try to avoid vertical
pipe runs (especially downhill pipe runs).
Table 1. Transducer distance from turbulence and readin accuracy
Upstream Downstream % Accuracy
20 Diameters 10 Diameters ±1% to 3% of full scale
10 Diameters 5 Diameters ±3% to 5% of full scale
7
5 Diameters 2 Diameters ±5% to 10% of full scale
Accuracy is dependant on flow profile, and is related to the percenta e of sound
reflectors and their size variation and distribution.
Fi ure 1 provides strai ht run examples.
INSTALLATION PROCEDURES
After you have performed the pre-install check and determined that the Doppler
flow meter will work for your application, follow these steps to install your meter.
To Install the Compu-Flow™ Doppler Ultrasonic Flow Meter:
1. Mount and connect the transducers
2. Mount and connect power to the electronics enclosure (see pa e 10)
3. Turn on power to the electronics enclosure usin the motherboard rear panel

INSTALLATION:
Compu-Flow™ Doppler
switch on the (front panel for portable) and follow display panel for meter set up
(see “Pro rammin ” pa es, for more information on confi urin your meter for
operation).
The clamp-on transducers are NEMA 6-rated and fully submersible. (For continuous
submersion secure sensors to pipe with approved epoxy.)
To Mount the Clamp-On Transducers to the Pipe:
1. Ensure the pipe surface is clean. Use sandpaper to remove all paint and
scale from the pipe surface if necessary.
2. Apply sonic el to the transducer lenses. For best results in most weather
conditions and heat, use Dow Cornin ® Hi h Vacuum Grease or the
supplied Nova ard® rease G661™.
Mountin and Connectin the Transducers
Attention
:

8
3. PLace the transducers side by side between 7 o’clock and 10 o’clock
on the pipe as shown in Fi ure 2. Place the transducers flush to the
pipe, facin the same direction. See Fi ure 3 for an example.
Note: Be careful with transducer placement. Air bubbles near the top of the
pipe or sediment on the bottom of the pipe can hinder successful
flow readin s. Place the transducers as shown in Fi ure 2.
Attention
:
Always apply sonic el to the transducer lenses before placin on the pipe.
The sonic el must be used to transmit the ener y from the transducer
crystals throu h the pipe wall and into the flow to be measured.

!

INSTALLATION:
Compu-Flow™ Doppler
4
.
Use
the
supplied
chain
and
bun ee
cord
to
strap
the
transducers
in
place,
Figure 2. Clamp-on transducer placement
Flow
Transducers
12 o’clock position
6 o’clock position
Cross-section of pipe with mounted
transducers
Electronics enclosure
9
4
.
Use
the
supplied
chain
and
bun ee
cord
to
strap
the
transducers
in
place,
securin them ti htly to the pipe. Fi ure 3 provides an example of two
properly mounted clamp-on transducers.
5. Small pipes below 2” do not permit side by side mountin .
Pipes 2”-1” diameter – mount sensors 90° apart
Pipes below 1” diameter – mount sensors 180° apart
Fi ure 3. Clamp-on transducers secured with a SS ½” ear clamp band

Compu-Flow™ Doppler
ELECTRICAL CONNNECTIONS:
Transducer wiring:
If your Doppler sensors are not yet connected to the electronics control
panel, open the panel, and use fi ure 4 as a uide to make the proper wirin
for the 4 transducer cables: Black (-12VDC), Red (+12VDC), Green (Echo),
White (Si nal).
Fi ure 4.
To Connect Input Power to the Electronics Enclosure:
Note: You can either use AC power or DC/ battery power to operate your
Doppler flow meter.
1. If you are usin AC power: (wall module only)
If not already connected, supply input power to the electronics
enclosure by routin the power cable throu h the appropriate
enclosure base openin .
□ Use a Nema 4Xcable land and a cable backin nut to securely fasten
the input power cable to the electronics enclosure.
Plu AC Power Module into the appropriate outlet.
10