- Mon Sep 21, 2015 2:56 pm
#29607
I would love to have a flow meter, and I just need a "it flows" / "it does not flow" scale: it would be perfect to detect water leakage while the house is empty, and trigger a remote alarm. However, I would not feel at ease putting a cheap flow meter in the middle of the circuit.
- Mon Sep 21, 2015 7:07 pm
#29619
Hi, all. I don’t really know a lot about this sort of measurement, but based on the limited information we have:
It clips onto a pipe.
The pipe size doesn’t seem to be important (guessing needs to be calibrated).
All the examples that I have seen are copper (but could be calibrated).
It measures water flow.
That taken:
I can see two ways to go at this:
Both have a transmitter at one end of the unit and a sensor at the other end (a bit obvious, but it doesn’t need the pipe to be cut).
Both involve the Doppler Effect.
The first: (and not the way I think it’s done) is to transmit a continuous signal at and one end. Calculate any changes in frequency recieved at the other end as water flow. Far too much maths or external circuitry to be viable.
The second: “ping” the pipe with a single signal then detect the two different signals at the receiver.
The first will be transmitted through the copper at about 4600M/S.
The second through the water at about 1433M/S.
Assuming the transmitter is down stream, the greater the flow, the greater the difference in the time difference between the two “pings” being received.
Then some maths gives you the water flow.
As for the reporting:
Each item holds a different quantity of water.
Each item has a different flow rate.
If only one item is drawing water we can report it accurately.
If two items are drawing water, we can have a good guess.
At the end of the day who is going to check exactly what is reported and if you do & find it’s not accurate who is going to care?
The transmitter & sensor:
I would guess some type of piezoelectric in direct contact with the pipe for both.
Anyway just my random thoughts.
It clips onto a pipe.
The pipe size doesn’t seem to be important (guessing needs to be calibrated).
All the examples that I have seen are copper (but could be calibrated).
It measures water flow.
That taken:
I can see two ways to go at this:
Both have a transmitter at one end of the unit and a sensor at the other end (a bit obvious, but it doesn’t need the pipe to be cut).
Both involve the Doppler Effect.
The first: (and not the way I think it’s done) is to transmit a continuous signal at and one end. Calculate any changes in frequency recieved at the other end as water flow. Far too much maths or external circuitry to be viable.
The second: “ping” the pipe with a single signal then detect the two different signals at the receiver.
The first will be transmitted through the copper at about 4600M/S.
The second through the water at about 1433M/S.
Assuming the transmitter is down stream, the greater the flow, the greater the difference in the time difference between the two “pings” being received.
Then some maths gives you the water flow.
As for the reporting:
Each item holds a different quantity of water.
Each item has a different flow rate.
If only one item is drawing water we can report it accurately.
If two items are drawing water, we can have a good guess.
At the end of the day who is going to check exactly what is reported and if you do & find it’s not accurate who is going to care?
The transmitter & sensor:
I would guess some type of piezoelectric in direct contact with the pipe for both.
Anyway just my random thoughts.
- Fri Sep 25, 2015 11:01 am
#29858
I like to see something like this for my aquarium. Right now, there's not a good way to measure water in/out when using a sump with an overflow. So we use things like float switches to prevent overflows if the drain plugs for some reason. I've considered inline flow meters, but with saltwater any metal in contact with the water is a very bad idea. It can contaminate the water and even low levels of copper can cause lots of death in the system. So a non-contact way to measure flow would be very welcome. If I could clamp one over the input and output pipes, I can use the flow difference to calculate if I'm going to have a problem. It could also be useful to automating water changes etc..
I saw the kickstarter, but I'd need at least 4 of them to really get the job done. That's just more than I'm willing to spend on convenience features.
I'd also like it for measuring my sprinkler system usage more accurately etc... I'll have to read up on the theory of it, I don't know much about measuring flow in a pipe.
I saw the kickstarter, but I'd need at least 4 of them to really get the job done. That's just more than I'm willing to spend on convenience features.
I'd also like it for measuring my sprinkler system usage more accurately etc... I'll have to read up on the theory of it, I don't know much about measuring flow in a pipe.
