Clamp-On Ultrasonic Flowmeters v Electro Magnetic Flowmeters

Published 08 Nov 2016

  • By Chris Dodds : estimated reading time 4 minutes

 a Competitive Comparison Analysis

by Katronic, a specialised UK manufacturer of Clamp-on Ultrasonic Flowmeters.

In this following article, we consider the pros and cons of installing ultrasonic clamp-on or electromagnetic (magmeter) type flow meters. We apply some cost-benefit analysis to establish conclusive evidence of the value-engineering savings and ROI to be derived from the specification and installation of ultrasonic clamp-on flowmeters.

Ultrasonic Flow Meters

Call T&D for Katronic Flowmeters


A magnetic flow meter (magmeter) would be expected to give an accuracy of anywhere between 0.15% and 2% depending on the manufacturer and the application requirements. Katronic ultrasonic flowmeters have an accuracy of 1-3% of measurement.

Pipe range

The range of a magmeter would be anything from 5mm to 2m depending on the supplier.

Ultrasonic flowmeters cover a range of 10mm to 3.5m with only two different sensor types.


The lowest cost magmeters start at > £1,000.00 but can exceed up to £20,000.00+ depending on the size of the pipe. Clamp-on flowmeters would cost between £ 3,000 and £ 6,000.00 depending on the meter configuration required.

Clamp-On Ultrasonic Flowmeters v Electro Magentic Flowmeters By Katronic Hazardous Area Flowmeter - KATFlow 170 Katronic

Hazardous Area Flowmeter – KATFlow 170 Katronic

Application limitations

Magmeters cover a large range of liquids, however the medium MUST be conductive. One of the biggest problems with these type of flowmeters is that they are not able to measure liquids such as hydrocarbons and condensates. Ultrasonic flowmeters will measure virtually any liquid provided that the solid or gaseous content is not too high.

Also unlike magmeters the pipe condition does have an effect on performance.

Flow range

Information available on magmeters would indicate a flow velocity range of 0.5 m/s – 10 m/s.

Katronic ultrasonic flowmeters cover a flow velocity range of 0.01 m/s – 25 m/s.

Clamp-On Ultrasonic Flowmeters v Electro Magentic Flowmeters By Katronic KATflow 200 Ultrasonic Clamp-On Flowmeter (Portable)

Katronic KATflow 200 Ultrasonic Clamp-On Flowmeter (Portable)


Magnetic flowmeters are an in-line device and therefore are susceptible to pressure changes and do cause a pressure drop across the meter. Clamp-on flowmeters are completely independent of pressure.

Installation / Commissioning

It is essential to break into the flow line to fit a meter and it may be necessary to weld flanges onto the pipeline. The fitting of an electromagnetic flowmeter is costly, both in material and manpower and involves shutting down the process which would be costly and is sometimes impossible.

Clamp-on ultrasonic flowmeters are completely free from installation and commissioning concerns and involve zero shut down time.

No Cutting. No Welding. No Cost.

Servicing / Calibration

Magnetic meters can be susceptible to damage and loss of calibration owing to particulate in the liquid and the general process condition. It would be recommended to remove the flow meter for checking on a regular basis thus incurring additional shut-down and cost. This is not required with the Katronic range of clamp-on meters.

Return of Investment Comparisons

Clamp-On Ultrasonic Vs Alternative Metering Technologies

Base Data Clamp-On Ultrasonic Meter Turbine Flowmeter Vortex Flowmeter Electromagnetic Flowmeter Orifice Plate
Meter Capital Costs 150mm OD, 1500 l/min £2,750.00 £800.00 £1,250.00 £1,800.00 £1,250.00
Engineering Costs £60 per hour £30.00 £1,920.00 £960.00 £960.00 £1,920.00
Installation Costs £50 per hour £200.00 £400.00 £400.00 £400.00 £400.00
Commissioning Costs £50 per hour £50.00 £50.00 £50.00 £50.00 £50.00
Costs Due To Loss Of Production 1000 per hour £0.00 £8,000.00 £8,000.00 £8,000.00 £8,000.00
Pumping Costs Due To Pressure Loss £/10 years £0.00 £4,400.00 £4,400.00 £0.00 £4,400.00
Mean Time Between Failure MTBF Years 10 1 5 10 2
Repairs/Calibration #/10 years 1 10 2 1 5
Cost To Repair 10 years £250.00 £2,500.00 £500.00 £250.00 £1,250.00
Losses Due To No Metering (Per Year) 1 pence/1000 l = £7,884
10 years = £78,840
Total Costs £3,280.00 £18,081.00 £15,567.00 £11,471.00 £17,277.00


Clamp-On Ultrasonic Flowmeters v Electro Magentic Flowmeters By Katronic - Ultrasonic Flow Meters

Katronic Ultrasonic Flow Meters

Benefits of CLAMP-ON ULTRASONIC Meters

  • No shut down or loss of production
  • No costly or risky engineering work
  • No pressure drop within the pipe or risk of leakage
  • No contact with the fluid (therefore hygienic)
  • Quick and easy installation and measurement
  • Low maintenance
  • Flow profile compensation for changes in temperature, density and viscosity
  • High temperature tolerance
  • Cost-effective solution, particularly on a large pipes
  • Numerous pipe diameters and materials

Should you require competitive quotation or assistance with the specification and supply of Flowmeters please either complete the application form below or call T&D Sales Engineers – contact T&D to discuss hazardous area flowmeters for installation in potentially explosive atmospheres.

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Clamp-On Ultrasonic Flowmeters v Electro Magnetic Flowmeters

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