Handheld Ultrasonic
FlowMeter
For Clean Liquids
FDT-21
U Accuracy 1%
U Repeatability 0.2%
U Positive, Negative and Net Totalizer
U 4-Line LCD Display
U Clamp On Transducers
U RS232 Output
FDT-21 ultrasonic flowmeter is designed to measure
the fluid velocity of liquid in a full/closed pipe. It is a
handheld measurement system which is both easy to
install and use. The FDT-21 operates according to the
difference in the transit time of flight measured, and
determines the flow velocity by measuring the travel
time of a pulse from one transducer to the next.
Flow in the same direction takes less time to travel to
the second transducer than does flow in the opposite
direction. Electroacoustic transducers receive and emit
brief ultrasonic pulses through the liquid of the pipe.
Transducers are vertically placed at both sides of the
measured pipe. Sensors are placed on the pipe and
fastened by means of a clamp. The display will quickly
show the flow velocity. The FDT-21 can be used for
metallic, plastic and rubber tubes.
E
Specifications
Accuracy: ±1% of reading >(0.2m/s) 0.6 ft/s
Repeatability: 0.2%
Linearity: 0.5%
Response Time: 0 to 999 seconds (user configured)
Velocity: (±0.01 to 30 m/s) ±0.03 to 105 ft/s bi-directional
Temperature Range:
Standard: 0 to 70ºC (32 to 158ºF)
With High Temp Transducers: 0 to 160ºC (32 to 320ºF)
Pipe Size: DN 20 to 100 mm (0.75 to 4") standard
[up to DN 6000 mm (236") with optional transducers]
Transducer Frequency: 1 MHz
Rate Units (User Configured): Meter, feet, cubic meter,
cubic feet, USA gallon, oil barrel, USA liquid barrel, imperial
liquid barrel, million USA gallons
Totalizer: 7-digit totals for positive, negative and net flow
Liquid Types: Most liquids including clean water, sea water,
waste water, chemical liquids, oil, crude oil, alcohol, beer,
and more
Suspension Concentration: ≤20,000 ppm (may contain
very small amounts of air bubbles)
Pipe Material: All metals, most plastics and fiberglass
Security: Programmable lock-out code
Display: 4 x 16 english letters
Communications: RS232C (baud rate from
75 to 115,200 bps)
Transducer Cable Length: 5 m (15')
Power: 3 “AAA” Ni-H built-in batteries (included) with 90 to
230 Vac charger, fully charged lasts over 12 hrs.
Data Logger: Built-in, stores over 2000 lines of data
Totalizer/Calibration: 7-digit press-to-go for calibration
Housing: ABS plastic with aluminum alloy protective
carrying case
Case: NEMA-4 (IP65)
Dimensions: 100 H x 66 W x 20 mm D (3.9 x 2.6 x 0.8")
Weight: 514 g (1.2 lb)
E-1
All accessories shown
smaller than actual size.
FDT-21-M2, medium pipe,
standard transducer
FDT-21, comes complete with
3 “AAA” batteries, small pipe
standard and high temperature
transducers (S1 and S1H), acoustic
gel, tape measure, plug-in charger,
RS232 cable, transducer cable,
rugged carrying case and
operator’s manual, shown
smaller than actual size.
FDT-21-S1H, replacement
small pipe, high-temperature
transducer
FDT-21-M2H, medium
pipe, high-temperature
transducer
FDT-21-HM, medium pipe,
aluminum transducer
Parameters HS-TypeHM-TypeS1-TypeM2-TypeL2-Type S1H-TypeM2H-Type
20 to 100DN 50 to 100DN 20 to 100DN 50 to 700DN 300 to 6000DN 20 to 100DN 50 to 700DN
Pipe Size (mm)
Pipe Size (inch)
³⁄₄ to 4
2 to 28
³⁄₄ to 4
2 to 28
12 to 240
³⁄₄ to 4
2 to 28
Aluminum Alloy
ABS
Alloy
Special
Material
High-Temperature Materials
1 MHz
Frequency
Calibrate with the main unit
Calibration
Magnetic
Non-magneticMagnetic
Magnetism
0 to 70°C (32 to 158°F)
0 to 160°C (32 to 320°F)
Temperature
NEMA 4 (IP65)
Protection Class
90 x 85 x 24
71 x 37 x 40
Dimensions (mm) 200 x 25 x 25 280 x 40 x 40 45 x 30 x 30 71 x 37 x 4088 x 44 x 50
Weight g (oz)
250 (8.8)
1080 (38)
75 (2.6)
259 (9.1)
650 (22.9)
94 (3.3)
259 (9.1)
Fresh water, salt water, chemical liquids, oil, crude oil, alcohol, beer, etc.
Liquid Types
Suspension
≤20000 ppm, may contain very small amount of air bubbles
Concentration
All metals, most plastics, fiberglass, etc.
Pipe Material
Dedicated
Standard length 5 meter x 2, can be extended to 10 meter x 2 or 15 meter x 2
Shielded
Transducer Cable
To Order Visit omega.com/fdt21 for Pricing and Details
Model No.
FDT-21
Description
Handheld transit-time ultrasonic flowmeter (includes S1 and S1H transducers)
Comes complete with 3 “AAA” batteries, small pipe standard and high temperature transducers (S1 and S1H), acoustic gel, tape measure,
plug-in charger, RS232 cable, transducer cable, rugged carrying case and operator’s manual.
Accessories
Model No.
FDT-21-S1
FDT-21-S1H
FDT-21-HS
FDT-21-HM
FDT-21-M2
FDT-21-M2H
FDT-21-L1
FDT-21-GREASE-S1
FDT-21-GREASE-S1H
Description Replacement small pipe standard transducer Replacement small pipe high temp transducer
Small pipe aluminum transducer
Medium pipe aluminum transducer
Medium pipe standard transducer
Medium pipe high temp transducer
Large pipe standard transducer
Acoustic gel for standard transducers
Acoustic gel for high-temperature transducers
Ordering Example: FDT-21, handheld transit-time ultrasonic flowmeter.
E-2
Weight g (oz) Pipe Size mm (inch)
75 (2.65)
20 to 100 (0.75 to 4)
94 (3.32)
20 to 100 (0.75 to 4)
250 (8.82)
20 to 100 (0.75 to 4)
1080 (38.09)
50 to 700 (2 to 28)
259 (9.1)
50 to 700 (2 to 28)
259 (9.1)
50 to 700 (2 to 28)
650 (22.9) 300 to 6000 (12 to 236)
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