Ultrasonic Flowmeters

RS Hydro offer an extensive range of ultrasonic flow meters for sale and rental. The use of non-invasive, ultrasonic flow measurement offers great benefits in many applications. With the use of ultrasonic transducers clamped to the outside of pipework, there is no downtime or disruption of flow. RS Hydro also offer installation, maintenance, calibration and consulting services.

RS Hydro supply the very latest portable ultrasonic liquid flow meter technology, which can measure liquids up to 250ºC , can be used with most pipe materials and linings and on pipes from 10mm to 7000mm diameter. Minimal installation, low cost and no pressure loss make portable ultrasonic flow measurement the best choice for many applications.

Fixed installation ultrasonic flowmeters with clamp-on, spool piece or wetted transducers.

Inline and insertion flowmeters that use ultrasonic technology, featuring the industry leading SITRANS range of transit time flowmeters from
Siemens.

Ultrasonic flow meters suitable for hazardous area applications including offshore platforms and zone 2 areas. Our intriniscally safe flowmeters are extremely rugged and can be used for measuring almost any liquid.

The non-contact ultrasonic flow meter is a non-invasive flow meter available in two formats: transit time and doppler. Both technologies feature clamp on designs with transducer arrangements that can detect in-situ flow rates from outside the pipework, without any interruption to flow or process. Transit time flow meters, or also known as 'time of flight' meters are mainly consigned to the measurement of clean liquids, although many flow measurement devices have a maximum tolerance of 5% solids. The principle behind this type of non-intrusive clamp-on (strap on) flow meter is that acoustic waves with a frequency of >20kHz are emitted from one transducer to the other side of the pipe back to the opposite transducer requires less time than when travelling in the opposite direction. The differential transit time of the synchronised signals is proportional to the flow rate of the fluid.

GE Panametrics PT878

The GE Panametrics PT868 and PT878 flow meters are designed to withstand rugged use in industrial applications. With superior diagnostics, functionality and accuracy this flow meter is regarded as leading edge technology. The PT878 utilises an acoustic signal-coding technique to make accurate measurements in flows containing gas bubbles or entrained solids. We would recommend this flow meter to professionals who want the most from a portable ultrasonic flow meter. This meter has two external inputs which makes it ideal for a heat metering survey.

Advantages of Clamp-On Flowmeters

GE Panametrics PT878GC Portable Ultrasonic Gas Flow Meter

Non-invasive flow monitoring
Measurement of non-conductive fluids
Easily installed clamp-on sensors with no interruption to flow
Wide range of pipe materials and sizes: 12.7-7600mm
Process temperatures from -40°C to 200 °C
Integrated wall thickness measurement

Comparison of Ultrasonic vs Other Types of Meter

Type of Meter	Advantages
Coriolis	Able to measure flow in medium and large pipe sizes
Vortex	less intrusive low flow capability
Magnetic	can measure gas, steam & non-conductive liquids
DP	less intrusive little or no pressure drop less need for recalibration
Turbine	less intrusive; not subject to wear - no moving parts

Applications for Ultrasonic Flow monitoring

Portable ultrasonic flow meters can measure almost all light homogeneous fluids including water, wastewater (<5% solids) and hydrocarbons. The basic requirement is that the fluid can conduct ultrasound and have an acceptable axis-symmetrical flow. Click here to see the many fluids that ultrasonic devices can measure.

Typical applications include:

Water distribution flow metering
Leak Detection
Wastewater flow-metering
Building Services
Inspection of fixed installation meters
Power/Energy Management
Chemical / Pharmaceutical
Petro-Chemical
Pump inspection
Food/Hygienic flow-monitoring
Steel
Light Industrial
Survey work

Flowmeter Specifications

Although specifications are different between the various manufacturers, the following is intended as a guideline to their performance and specification.

Flow Range	0.01-20m/sec (Bi-Directional)
Accuracy	±0.5-3% of reading
Repeatability	Typically ±0.5%
Pipe Size	12.7-7600mm
Operating Temperature
Transducers	-40°C to +200°C
Transmitter	-10°C to 50°C
Datalogging	Typically>100,000 data points, time stamped
Output	4-20mA, pulse
Power	Built-in battery with external 12v input, 8-36 hours operation
Dimensions	Typically 250 x 150 x 40mm
Weight (Control Unit)	Typically 3-5lbs (1-2kg)

Portable Flow Meters : Technical Notes

For optimum accuracy the following conditions must apply:

	Requirement
Location	At least 10 diameters of straight-length pipework must exist upstream of the measurement point, and 5D downstream. Ideally these distances should be as large as possible.
Wall Thickness	For optimum accuracy, the pipe wall thickness should also be measured. Some meters are supplied with ultrasonic wall thickness gauge
Liquid Medium	It is essential that the type of fluid is known. Also that there are no air bubbles and that the solid content does not exceed 5%.
Pipe Condition	The pipe wall exterior should be free from dirt, paint or corrosion. For optimum accuracy the interior wall should also be free from deposits or corrosion.