measuring water flow in a pipe - Page 1
Forum section: electronics / beginners

author: engineheat
author_rank: Frequent Contributor
timestamp: September 08, 2021, 04:29:41 pm
content: Hi,I need to measure water flow rate in a home plumbing system. I need a sensor that can be clamped onto a pipe (exact diameter not determined) and can measure the water flow rate with a minimum resolution of 1 measurement per 5 seconds. It would need to store the data somehow so that I can get the data into a PC later. Better yet, if the sensor can wirelessly transmit data to a PC or server, that'd be awesome.Do you know of any such sensors under $300?Thanks

author: Benta
author_rank: Super Contributor
timestamp: September 08, 2021, 04:58:44 pm
content: Available from many sources, based on magnetic measurement. But whether you can get one under $300? No idea.

author: CaptDon
author_rank: Super Contributor
timestamp: September 08, 2021, 05:20:12 pm
content: They make a shoe type device that clamps to the pipe and uses a bit of something like heat sinkcompound to increase the acoustic coupling. They work on the doppler effect to measure flowspeed in ins/sec or ft/sec. You must know the surface area of the inside diameter of the pipe toconvert to gals/min or what ever. Surface area being pi x (R squared). Make the I.D. measurementaccurately because being off even a tiny bit leads to a huge error.

author: ledtester
author_rank: Super Contributor
timestamp: September 08, 2021, 05:58:50 pm
content: Search for "ultrasonic flow meter" -- it'll bring up a lot of industrial devices.There are also a few offerings aimed at the residential market -- like the StreamLabs Home Water Monitor which has a Wifi/cloud connection.

author: engineheat
author_rank: Frequent Contributor
timestamp: September 11, 2021, 06:37:22 pm
content: Quote from: ledtester on September 08, 2021, 05:58:50 pmthanks. Can you recommend a few other than StreamLabs? I'm mostly interested in those aimed at residential market. I only found expensive industrial ones.

author: ledtester
author_rank: Super Contributor
timestamp: September 11, 2021, 08:37:12 pm
content: Flume 2 is another non-invasive monitoring system that measures the magnetic pulses that your meter gives off - so it's good for measuring total consumption but not a branch. They say it's compatible with 98% of household meters in the US.

author: engineheat
author_rank: Frequent Contributor
timestamp: September 16, 2021, 07:41:04 pm
content: Quote from: ledtester on September 11, 2021, 08:37:12 pmThanks. I'm also looking into meters that can be fit in-line into the pipes. Obviously this would require a plumber but it seems in-line meters tend to be cheaper and simpler than the clamp-on sensors.I need a meter that can be used off the shelf (as opposed to something that I'd need a Raspberry Pi for...), can store data, and can measure at a sufficient frequency (say, once per few seconds). Do you know of any such devices?Thanks

author: StuartA
author_rank: Regular Contributor
timestamp: September 16, 2021, 08:18:50 pm
content: One of the most basic flowmeters is the turbine - just a little propeller which turns faster as the flow increases. typically used in say 1/2 inch diameter pipes. I've used them at work and I bought one for home use (watering the lawn) but don't know what I did with it. If you can get one with standard compression fitting to match the diameter of your pipe, a plumber should not be necessary; just find a youtube dealing with compression fittings if you need guidance.

author: armandine2
author_rank: Frequent Contributor
timestamp: September 17, 2021, 07:07:48 am
content: There are a couple of good pages on this in Whitakers Electronics Handbook - the edition attached is now reasonably priced

author: IanB
author_rank: Super Contributor
timestamp: September 17, 2021, 07:25:33 am
content: Quote from: engineheat on September 08, 2021, 04:29:41 pmIt's not easy or practical to do this. Flow meters can't be clamped onto the outside of a pipe, they have to be inserted into the pipe (you will have to break the pipe to install the flow meter). Typical meters are also likely to need calibration.One possible option (if your utility water meter is conveniently accessible) is to position a camera module pointing at the meter face and then use OCR to read the meter in software (using a Raspberry Pi or something). Unfortunately, most water meters tend to be outside and underground, so this would only work temporarily with a battery supply and using wi-fi to transmit the reading.

author: DIYDan
author_rank: Newbie
timestamp: September 20, 2021, 06:03:01 am
content: On farms, often the resource consent requires a flow meter with the results uploaded to a website that the council have access too such asFlow Meters & Telemetry. The inline types seem much more durable. I'd imagine the tricky part would be the telemetry to a PC, otherwise there's a lot ofUltrasonic Water Flow Meter TDS-100F1these sorts of things around. I'd love to have a portable one such asTUF-2000H-TM-1+TS-2 Ultrasonic Flow Meter FlowmeterI't would be handy to calibrate a plate heat exchanger.

author: geggi1
author_rank: Frequent Contributor
timestamp: September 20, 2021, 10:02:38 am
content: If you go for a ultrasonic flow meter you need to have certain lengths of straight pipe before and after the flow meter. Any turbulence and cavitation will give inaccurate readings. normally its 10 pipe-diameters up front and 5 after the flow meter.There is a lot of information about ultrasonics that can be found on the internet. The link below gives you the most essential stuff.https://www.atratoflowmeters.com/ultrasonic-flow-meter-installation/

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 20, 2021, 03:19:50 pm
content: Ultrasonic flow meters are expensive because they're made for the industrial market. Price does not matter much there, but it has to last 20 years or longer with preferably no maintenance at all.If you want to do it cheaply, then bu an EUR5 flow meter, saw a piece out of the pipe and install some couplings, and those parts are easily more expensive than the flow meter itself, and introduce possible points of failure / leakage / contamination.

author: StuartA
author_rank: Regular Contributor
timestamp: September 22, 2021, 02:35:53 pm
content: This is the cheap turbine meter I boughthttps://electropeak.com/yf-s201-water-flow-sensor.I never got around to using it. At $11, it may be worth a look.

author: Kleinstein
author_rank: Super Contributor
timestamp: September 22, 2021, 04:51:51 pm
content: There are quite a lot of offers of used (end of calibration) heat flow meters. These have a flow meter and 2 temperature sensors.The flow meter is either turbine type or ultrasonic. The turbine types may give you a simple magnetic signal to pic up and count.