Clamp-on Ultrasonic Flow Measurement?
Clamp-on Ultrasonic Flow Measurement?
(OP)
Hello, I've searched the internet and the forums and I can't seem to find a lot of good information on this. I'm going to be purchasing a portable non-intrusive clamp-on flow meter for use in measuring water flow in chilled water and heating water hydronic systems. I'm just looking for product recommendations and general experiences with this type of flow meter.
My application will be analyzing existing hydronic systems used in HVAC applications, so chilled water temperatures will range from 40-54°F and heating water temperatures between 100 and 250°F (temperatures will be fairly constant during measurement). Water velocities should be below 10 fps in most applications, but I wouldn't be surprised if they exceed that in some circumstances. Pipe diameters should be under 10" in most applications, but capability for larger pipes would be nice. This will be used for taking quick field measurements and for doing some temporary datalogging to determine existing flow conditions.
I'd just like to know if anyone has had any good or bad experiences with certain brands or if there are any solid industry standards out there I should be looking at. I'm currently looking at Onicon's F-4400, and hopefully will be receiving one to demo before purchasing soon. I also plan on giving Siemens a call tomorrow about their SITRANS FUP1010. I'd also like to know if anyone has any general information on them based on experience.
Thanks.
My application will be analyzing existing hydronic systems used in HVAC applications, so chilled water temperatures will range from 40-54°F and heating water temperatures between 100 and 250°F (temperatures will be fairly constant during measurement). Water velocities should be below 10 fps in most applications, but I wouldn't be surprised if they exceed that in some circumstances. Pipe diameters should be under 10" in most applications, but capability for larger pipes would be nice. This will be used for taking quick field measurements and for doing some temporary datalogging to determine existing flow conditions.
I'd just like to know if anyone has had any good or bad experiences with certain brands or if there are any solid industry standards out there I should be looking at. I'm currently looking at Onicon's F-4400, and hopefully will be receiving one to demo before purchasing soon. I also plan on giving Siemens a call tomorrow about their SITRANS FUP1010. I'd also like to know if anyone has any general information on them based on experience.
Thanks.





RE: Clamp-on Ultrasonic Flow Measurement?
Dont know about the portable version on this - from memory, installing these on the pipe requires specialist skills.
RE: Clamp-on Ultrasonic Flow Measurement?
I heard a salesman recently say that the next gen electronics box for 1010 is due out this fall. As much as I'm impressed with this clamp-on, if it were me, I'd wait for the next gen, particularly for datalogging.
The only downside with ultrasonics is that it can not get a reading if the pipe really scaled up on the inside: insufficient signal strength. Works great on treated water, new and unscaled pipe, but on 35 year old CS pipes running untreated water? Toss of the coin as to whether you'll get a reading or not. But that's not just Siemens, that's any of 'em. Actually it's not a bad indicator of internal scaling, if anyone cared.
RE: Clamp-on Ultrasonic Flow Measurement?
However be aware of the issues of UT meters.
You need a good clean surface to clamp to, both inside and out, so any painted, coated or galvanized pipes can be difficult to get good readings.
You need 100% liquid, no bubbles or gas pockets
Set-up requires a certain length of straight pipe to get the signal return and avoid high turbulence areas
Set-up can take a while to get a reliable fixing and then accidentally nudging one of the clamps sends it off or leads to breaks in readings.
I don't know what difference temperatures make to the speed of sound in water, which is your key measurement issue - you would need to check to see how this variance, if any, is input into the machine to get a reliable reading.
Portable machines tend to be single path which are good, but need relatively stable flow. multi-path tends to reduce the impact of swirl and turbulence inside the pipe, but you won't often get that on a portable system.
If it was me I would hire one to get to grips with the issues or "try before you buy"
If you're going to do it yourself, you will need to factor in some training costs from the vendor otherwise you'll waste a lot of time figuring it all out.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Clamp-on Ultrasonic Flow Measurement?
https://www.youtube.com/watch?v=KRdoh2bBoYQ
RE: Clamp-on Ultrasonic Flow Measurement?
RE: Clamp-on Ultrasonic Flow Measurement?
The Siemens 1010 can tolerate some air and actually reports aeration as a unitless value.
The transit time transducer are super, but the doppler transducer set is merely an indication of flow, with no reasonable means of getting an absolute flow rate value and too slow in response to use as a flow switch. Save your money, skip the doppler option.
A 4" angle grinder with a wire brush does wonders for cleaning off the outside of the pipe.
Yes, temperature affects sonic velocity. The 1010 actually measures the sonic velocity of the medium at the start of a commissioning setup. I have no idea how.
The manual has a table with sonic velocities for water at 2°F intervals and a graph of ethylene glycol at various percentage concentrations.