Ultrasonic Liquid Flow Transmitter

INTRODUCTION

Valmax Ultrasonic Liquid Flow Transmitter (VLFT) is a type of flow Transmitter that measures the velocity of a fluid with ultrasound to calculate volume flow.
Ultrasonic transit time flow Transmitter measure the difference of the transit time of ultrasonic pulses propagating in and against the flow direction.

VLFT is affected by the acoustic properties of the fluid and can be impacted by temperature, density, viscosity and suspended particulates depending on the exact flow Transmitter.
The minimum maintenance cost is required because there are no moving parts, unlike mechanical flow meters.

VLFT’s STRENGTH

Minimum
Maintenance
VLFT has no moving parts and is highly durable, minimizing maintenance costs. (All stainless steel wetted parts)
High
Accuracy
VLFT can measure low flow up to 0.3 LPM and has a rangeability of 1:100, so it has high measurement accuracy and resolution.
Various
Applications
VLFT can be used for corrosive liquids.
No
Pressure Loss
VLFT is designed to minimize interference with flow in the piping.

VLFT Applications

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Semiconductor

Chemical Icon

Chemical

Factory Icon

Factory

Ship Icon

Ship

PRINCIPLE

PRINCIPLE

Ultrasonic flow Transmitter measure the difference between the transit time of ultrasonic pulses propagating with and against the flow direction. This time difference is a measure for the average velocity of the fluid along the path of the ultrasonic beam. By using the absolute transit times tup and tdown both the averaged fluid velocity ν and the speed of sound c can be calculated.

Using these two transit times, the distance between receiving and transmitting transducers L and the inclination angle θ, if we assume that sound has to go against the flow when going up and along the flow when returning down, then one can write the following equations from the definition of velocity:

By adding and subtracting the above equations we get,

where v is the average velocity of the fluid along the sound path and c is the speed of sound.

Calculate the volume flow rate and qV using the following expression as the average speed of v and the cross section of the measurement part of A.

TECHNICAL SPECIFICATIONS

Model No. VF-10
Fluids Water / D.I water / Coolant / Solvent / Chemicals
Flow Range DN15(½”) : 0.3 ~ 30 LPM
(Option : 0.5 ~ 50 LPM)
Accuracy ±1.0 %
Working Temperature -40 ~ 80 ℃
Working Pressure 0.6 ~ 20 bar
Material Stainless Steel 316L
Repeatability ±0.5 %
Linearity ±0.5 %
Power 24 VDC
Output 4 - 20 mA
Connection DN15(½”) : ½” PT Male

DIMENSION

Dimension