Transducers ultrasonic flow meter

Ultrasonic flow meter
Ultrasonic flow meter

Sitelab SL1168 is equipped clamp-on transducers made with SiteLab patented technology. Which is suitable for metal, PVC and other pipe materials, or lined pipe. The transducers use robust material with the high-performance piezoelectric crystals. With high accuracy and good performance during measurement.  so, it’s easy and convenient to install. Users only need to fix it on the pipe with the pipe straps and set up the transducer spacing according to the prompt calculation of the meter. It only  takes minutes to complete.

 Specifications :

  • Performance specifications.
  • Flow range : 0  ~  ±40 f t /s (0  ~  ±12m/s).
  • Accuracy : ±1.0%.
  • Repeatability: 0.2%.
  • Pipe size : 1 in to 40 in (25mm ~ 1200mm).

Functional specifications

  • Output : 0~9999Hz, OCT.
  • Power supply : 10 ~36 VDC or 10-24V AC,1A  (max).
  • Keypad : 16 (4X4) touch key-press.
  • Display : 20X2 alphanumeric, back lit LCD.
  • Temperature range :
    • Transmitter: -10 °C ~ 50 °C
    • Transducer: 0 °C~60 °C
  • Humidity : Up to 99% RH, non-condensing.

Clamp-on Transducers Installation Methods

The Installation of Clamp-on Ultrasonic Flow-meters is simply. By applying the coupling compound on the bottom of the transducers and strapping them to the outside of the pipe. The V method installation on pipe size: 1” to16”(25 mm to 400 mm).

Ultrasonic Flow Meter


FDT-21 ultrasonic flow meter 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.


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 70°C (32 to 158°F).
With High Temp Transducers : 0 to 160°C (32 to 320°F).
Pipe Size : DN 19 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, liter, 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).

Pipe Size (mm)20 to 100DN50 to 700DN300 to 6000DN20 to 100DN50 to 700DN
Pipe Size (inch)3 ⁄4 to 42 to 2812 to 2403 ⁄4 to 42 to 28
MaterialAluminum AlloyABSAlloyABS
Frequency1 MHz
CalibrationCalibrate with the main unit
Temperature0 to 70°C (32 to 158°F)0 to 160°C (32 to 320°F)
Protection ClassNEMA 4 (IP65)
Dimensions (mm)200 x 25 x 25280 x 40 x 4091 x 44 x 5245 x 30 x 3071 x 37 x 40
Weight g (oz)250 (8.8)1080 (38)535 (18.5)75 (2.6)259 (9.1)
Liquid TypesFresh water, salt water, chemical liquids, oil, crude oil, alcohol, beer, etc.
Suspension Concentration≤20000 ppm, may contain very small amount of air bubbles
Pipe MaterialAll metals, most plastics, fiberglass, etc.
Dedicated Shielded Transducer CableStandard length 5 meter x 2, can be extended to 10 meter x 2 or 15 meter x 2


Model No.DescriptionWeight g (oz)Pipe size mm (inch)
FDT-21-S2HReplacement small pipe high temp transducer
FDT-21-HSSmall pipe aluminum transducer250 (8.82)20 to 100 (0.75 to 4)
FDT-21-HMMedium pipe aluminum transducer1080 (38.09)50 to 700 (2 to 28)
FDT-21-M2HMedium pipe high temp transducer259 (9.1)50 to 700 (2 to 28)
FDT-21-L2HLarge pipe high temperature transducer535 (18.5)300 to 6000 (12 to 236)
FDT-21-GREASE-S1Acoustic gel for standard transducers
FDT-21-GREASE-S1HAcoustic gel for high-temperature transducers
FDT-21-UPSUniversal power supply

Ordering Example : FDT-21, handheld transit-time ultrasonic flow meter

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