Clamp-on – Ultrasonic Flow Measurement

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Ultrasonic Flow Measurement Theory – Doppler & Transit TimeStandards & SpecificationsProduct Application – Where & How?Typical Product Features & Benefits

Clamp-on –Ultrasonic Flow Measurement

Ultrasonic Flow Measurement Theory – Doppler vs. Transit

Time Doppler is only suitable for contaminated or aerated liquids.

Flow

Sensor Block

Liquid

Pipe wall

When ultrasound hits a moving particle or gas bubble The reflected sound can be detected and the frequency shift measured.The frequency change is proportional to flow velocity which is converted to volumetric flow rate by multiplying by the cross sectional area of the pipe.Typical liquid application?

4

Transit Time is suitable for clean liquids < 2% particles or contaminates

A B

Flow

Sensor Block

Liquid

Pipe wall

Time of Flight Ultrasonic Meters measure the Transit Time of a beam of UltrasoundFlow velocity is calculated from the difference in time taken for the sound to travel either upstream against the flow or downstream.Typical liquid application?

Ultrasonic Flow Measurement Theory – Doppler vs. Transit

Time

Dwyer Series UFB, UFC, PUB & PUF are transit time ultrasonic flowmetersUFB & UFB are

permanent mount units

Ultrasonic Flow Measurement Theory – Doppler vs. Transit

Time

PUB & PUF are portable units

UFC & PUF also feature data logging capability

Standards & Specifications

Product Specification: This will vary for different manufacturers and products but the following should be expected as a minimum –

Accuracy: +/1-3% of flow reading for > 0.5m/sFlow velocity range: 0.5 to 5m/sPipe range: 25 – 100 mm DiameterFor Use on Steel, Copper and Plastic PipesVolume output: PulseFlow rate output: Optional 4-20mAZero offset < +/-0.005m/sRepeatability < +/-1%

Product Application – Where & How?

Application/Use:Hot water metering and flow measurementFlow measurement for Heat MeteringCold water sub-metering and flow measurementChilled water metering and flow measurementFlow measurement for chilled water energy meteringPotable water sub-metering and flow measurementProcess water metering and flow measurementUltrapure water measurementWater/Glycol applications

Product Application – Where & How?The ultrasonic equipment expects a uniform flow profile as a

distorted flow will produce unpredictable measurement errors. Flow profile distortions can result from upstream disturbances such as bends, tees, valves, pumps and other similar obstructions. To ensure a uniform profile the transducers must be mounted far enough away from any cause of distortion such that it no longer has an effect.

Product Application – Where & How?Suitable pipe criteria will vary

with different manufactures and products information listed below is typical:

Typical Product Features & Benefits

Metered liquid flow rate and volumeEasy to install – no pipe cuttingClamp-on sensorsLimited intuitive programmingLower installed cost than in-line metersNon-invasive – no line pressure lossesDry servicingReliable – no mechanical moving parts