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Select Clamp-On Ultrasonic Flow Meter For Liquid Cheat Sheet (DRAFT) by [deleted]

Tips For Selecting A Clamp-On Ultrasonic Flow Meter For Liquid

This is a draft cheat sheet. It is a work in progress and is not finished yet.


A broad range of factors such as the type of liquid to be measured, pipe material and pipe size can influence your choice of clamp-on ultrasonic flow meter and selecting a suitable model requires an unders­tanding of the different features and options available. Here are 10 Top Tips to help you chose the most suited clamp-on ultrasonic flow meter for your liquid flow applic­ation


1. Why choose a clamp-on ultrasonic flow meter?
Flow meters which clamp on to the outside of the pipe offer many advantages over tradit­ional in-line flow meters: easy instal­lation, no moving parts, no pressure loss, no compat­ibility issues etc.

2. What are the two basic princi­ples?
Time of Flight, ultrasonic pulses are timed as they are transm­itted and then received within a pipe. Doppler Shift, where suspended solids and bubbles reflect an ultrasonic beam.

3. Which principle is best for me?
It depends on your applic­ation: clean liquids with little air or suspended particles are suitable for Time of Flight, whereas slurries or dirty water with entrained air or solids are suited to Doppler models.

4. What quick tips are available for proper instal­lat­ion?
Always take your time to read the instal­lation instru­ctions as this is critical for accurate and reliable readings especially for Time of Flight models. Install in recomm­ended straight pipe lengths avoiding vertical downward flow condit­ions, turbulent flows (unless Doppler) and heavily corroded pipes. Very small pipes need specialist meters for accurate and reliable results.

5. Are models for measuring heat energy availa­ble?
Yes there are several manufa­cturers offering ultrasonic heat meter versions which can calculate measur­ements in chilled and hot water systems, usually with a choice of energy management system compliant output protocols such as Modbus or BACnet.

Portable Flow Meter

Tips Continued

6. What if I have lined pipes?
Time of Flight ultrasonic flow meters can accomm­odate this feature during set-up where the user enters all of their critical pipe inform­ation / specif­ication to ensure accurate calcul­ation data for the flow measur­ement.

7. Can I use the same model on different sized pipe?
Yes, however it may be a requir­ement to purchase more than one set of pipe transd­ucers, since one size may cover the range of small pipes and another that of large pipes. Most portable ultrasonic flow meters come with a selection of transducer sizes and even principles in the carry case.

8. Is this principle MID approved within Europe?
The simple answer is no, as the ability of the installer to attach the measur­ement transd­ucers to the pipe incorr­ectly is always a possib­ility, which renders any guaranteed perfor­mance figures useless.

9. Can clamp-on ultrasonic flow meters be re-cal­ibr­ated?
Yes most flow calibr­ation companies will offer this service, however it may not be specific to your actual applic­ation parame­ters.

10. Is software available to program the meter and analyze stored data?
Yes, most manufa­cturers will offer some form of software support for their products. On low end models this may be just to import stored data, whereas on higher end models this may display real-time data, signal analysis and offer full meter set-up and config­ura­tion.