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[on:]

Dear All,

I want to log the water pressure coming into my house only when no one is using any taps in the house.
The pressure is never more than  45PSI. The main water line coming into house is 15mm. I had an IP camera looking at the gauge for some time now. I can easily install something inside the pipe, I do not want to reduce the pressure "significantly" by installing anything into the pipes.
I bought and learn with Arduino Mega.

Looking on the web I thought I need the following: 
a. Water pressure sensor.  I want to buy this:
http://sensing.honeywell.com/index.cfm?ci_id=140301&la_id=1&pr_id=145908

b. Water flow sensor recommend in this forum and on web:
http://www.seeedstudio.com/depot/water-flow-sensor-p-635.html?cPath=6&zenid=594b89701c7a2015a13064b67aed4f44

I hope to only record pressure when the flow meter indicate zero flow.

Your advise will be much appreciated.
I can buy digital data loggers It is very expensive +- UK £400. This will not allow me to learn anything.

Thank you,

[Reply #1 on:]

I want to log the water pressure coming into my house only when no one is using any taps in the house.

The why behind this would be interesting to know. Is there a problem you are trying to solve?

[Reply #2 on:]

Sure. The why.
A 130 year old house. I must share the Thameswater supply in London, UK (council water supply) with my neighbour. As a result I have no water in the house very often. I want to see patterns and see if should spend the few thousand pounds to have my own line brought to the front of the property. Ridiculous case as I pay full water rates yet only have a very reduced service. That is different matter, one cannot beat the system.

I thought to learn something from the issue and try to get an MRTG graph of my water pressure.

Till now I would look on the IP-cam to see if the pressure is normal so I can shower.

[Reply #3 on:]

fundutzi

The flow sensor is perfect for your needs, if the connectors are suitable etc

The pressure indicator is a bridge output device.  The low level output signal will require amplification and other circuit elements.  i would not start there.

This on the other hand would be about perfect:
http://cgi.ebay.com/Setra-Model-C206-0-100-psig-Pressure-Transmitter-Good-/120688428882?pt=LH_DefaultDomain_0&hash=item1c19974752

It is a current output device.  Put 12 volts on the red line and bring the black back to a 125  ohm resistor and then to ground, there will be a nice 0 to 5 volt signal across the resistor that corresponds to 0 to 100 psi.  Double the resistance to 250 ohms and the signal will be 0 to 5 volts over a 50 psi range.  It will go higher if the pressure is greater.  Be careful.  The pressure transmitter can be located hundreds of feet from the board.  This can be quite a convenience.

i know the label says 24 volts, but 12 will almost certainly work, particularly with a 125 ohm resistor.

jc

[Reply #4 on:]

Thank you very much.

I will proceed and give feedback with results.

Best regards