Series TFXD
Transit Time Ultrasonic Flow Meter, Clamp-on, Liquid, Single-Channel
Part 1. General
1.1 Scope
A. This section describes the requirements for an ultrasonic
flow measurement transmitter plus transducers.
B. Under this item, the contractor shall furnish and install the
flow measurement equipment and accessories as indicated
on the plans and as herein specified.
1.2 Submittals
A. The following information shall be included in the
submittal for this section:
1. Data sheets and catalog literature for
microprocessor-based transmitter and transducer.
2. Interconnection and dimensional drawings.
3. List of spare parts
Part 2. Products
2.1 Transit Time Ultrasonic Flow Meter
A. The transit time ultrasonic flow measurement system shall
be a microprocessor based transit time (time of flight)
measuring type providing an electronic output signal
proportional to the flow of liquid in closed piping systems
as may be required. It shall consist of a transmitter and one
transducer set connected by up to 990 feet [300 meters] of
cable.
B. Transducer:
1. Operating principle: Two ultrasonic transducers
function as both transmitters and receivers. Flow
measurement is made by transmitting acoustic
impulses alternately between two ultrasonic
transducers positioned lineally, a known distance
apart, on the outside pipe wall of a closed conduit.
Pulse travel time between the two transducers is
measured and the difference time calculated –
contrapropogation. Difference time is directly
proportional to fluid velocity, with a system
Reynolds Numbers correction factor applied.
2. Primary Sensor: The compression-mode acoustic
transducer shall contain a polarized Zirconium
crystal with impedance matched wave-guide.
a. Universal transducers shall operate on pipe
sizes ranging from 2” through 100” [50
through 2540 mm].
b. Small-pipe transducers shall operate on pipe
sizes from 1/2” through 2” [12 through 50
mm] and are specific to a pipe outside
diameter.
c. Transducer housing shall be PVC, CPVC,
Teflon, Ultem or Vespel.
d. Process connection shall be 1/2” NPT
e. Standard operating temperature shall be -40
o
to 250oF [-40° to +121° C]
f. Optional operating temperature shall be -40
o
to 400oF [-40° to +200° C]
C. Transmitter
1. Enclosure shall be NEMA 4X polycarbonate
2. Power supply shall be 115/230 VAC +/- 15% @
50/60 Hz or 9-28 VDC
3. Power consumption shall be 5 VA
4. Operating temperature shall be -40
o
C.
to 85
o
to 185o F [-40o
5. Input/output options: The transmitter shall accept
up to two input/output options to be installed.
Input/output options are field installable and
replaceable.
a. 4-20ma into 800 ohms; jumper
configurations for internal or external power
b. 2 form C, SPDT multi-purpose relays rated
0.5 A /200 VAC non-inductive
c. Pulse rate output, 0-2,500 Hz, open-
collector and turbine meter simulation
d. RS232C
e. RS485, ¼-node, 126 drops max
f. Data Logger, 200,000-events, Windows®
software utility
g. Dual-RTD input for liquid energy
measurements
6. Control and Programming
a. All parameter and commands shall be
entered via a personal computer, Windows®
software utility and infrared communicator
from outside the enclosure without opening
the enclosure.
b. Optional 4-key keypad.
7. Transmitter shall output a digitally synthesized
waveform from a discrete, field uploadable file.
8. Measurements shall be made by measuring
differential time of contrapropogating waveforms
using cross-correlation of data sets. Automatic
Reynolds Number corrections are applied.
9. Data collection shall be 20 MHz to 40 MHz.
D. Transmitter and Transducer Performance
1. Measuring range –40 to +40 FPS [-12 to +12 MPS]
2. Accuracy shall be ± 1 % of reading or ±0.01 FPS
[±0.003 MPS], whichever is greater.
3. Sensitivity is 0.001 FPS [0.001 MPS]
4. Maximum separation between transmitter and
transducer shall be 990 feet
E. Indication
1. Optional display shall be two lines: 8-digit LCD
with .7” high numerical values and 8-digit LCD
with 0.35” high alpha numeric values. Display is
backlighted with white LEDs.
2. Indicators for Run and Program modes and Relay 1
and Relay 2 status
F. Equipment
The transit time ultrasonic flow meter shall be a
Dynasonics Series DTFXD transmitter and Dynasonics
Series DTTN (standard temperature multi-size pipe),
DTTH (high temperature multi-size pipe) or DTTS
(standard temperature small-pipe) ultrasonic transducer.
Part 3. Operator Functions
3.1 Calibration
A. Flow meter calibration data shall be entered via a personal
computer, Windows® software utility and infrared
communicator. No additional equipment shall be required.
B. Internal self-diagnostics shall be available to assist in
installation and maintenance of the flow meter.
3.2 Transmitter Function Details
The following functions shall be provided:
A. The flow meter shall output, via infrared communications,
flow rate, positive, negative and net flow accumulations
and diagnostic data.
B. An optional local display shall display flow rate and total
accumulated flows.
C. The transducers shall be mounted at the measuring site and
shall be installed in accordance with the manufacturers
recommendations.
D. The transducers shall transmit and receive acoustic signals
to accurately measure liquid flow.
E. Operational range shall be adjustable be entering new data
via infrared communicator or optional keypad.
F. If equipped with an optional output module, the flow meter
shall be capable of zero to full scale output simulation to
assure proper operation with regards to flow charts or pump
control parameters.
H. There shall be no internal potentiometers or switches used
in programming or adjusting the transmitter.
I. The power to operate the transducers shall come solely
from the transmitter over the signal interconnection cable.
J. If the flow meter is equipped with dual alarm relays it shall
be programmable for rate of flow, batch/total accumulation,
loss of signal strength or system error.
K. The flow meter shall have a FLASH memory and shall not
require a battery to ensure protection of stored data.
L. Flow meter shall provide automatic Reynolds Number and
speed of sound compensation.
Part 4. Execution
4.1 Installation
A. Follow manufacturers recommendation upstream and
downstream straight pipe diameters and transducer
orientation.
B. Enter pipe and liquid configuration information into the
flow meter. The flow meter will calculate transducer
separation from the data entered.
C. Mount the transducers onto the pipe at the calculated
separation distance.
D. Additional cable for the transducers shall be RG59 coaxial.
All connections shall be 75 Ohm.
Part 5. Warranty
5.1 Terms
A. The manufacturer of the above specified equipment shall
guarantee for twelve (12) months from date of shipment
that the equipment shall be free from defects in design,
workmanship or materials.
B. In the event a component fails to perform as specified or is
proven defective in service during the warranty period, the
manufacturer shall promptly repair or replace the defective
part at no cost to the owner.
Part 6. Options
6.1 Related Equipment
A. Infrared Communicator DB-9 connection
B. USB to DB-9 converter
C. 36” [915 mm] x ½” [12 mm] stainless steel transducer
mounting straps
D. Dow 111 silicone grease
E. Transducer mounting track
Part 7. Spare Parts
7.1 Recommended Spare Parts
A.
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