Has anyone used a water Bridge Pressure sensor to attach to an Arduino.

It goes from 0 bar to 4 bar and I need to read it with an Arduino to switch on a pump when the pressure drops from 4 Bar to 2.5 Bar say.

Many thanks

Hi.
I never experimented with a water pressure sensor with the Arduino.
Can you share a link to the sensor?
Regards,
Sara

Hi Sara, hope this works, it’s not very good. https://www.datasheetarchive.com/pdf/download.php?id=b67185698a6ce2b887e130bea007b28c925aef&type=P&term=4ff6g
put some more info on but sorry not very clear. It uses 5v as vcc but through a 10k resistor.

Hi.
 
I’m sorry but I can’t help based just on that datasheet.
 
It seems to have two outputs. You’ll have to read the outputs to have an idea of the pressure.
It mentions that output A increases as pressure increases and output B decreases as pressure increases.
 
Regards,
Sara

The sensor is intended to be used in a whetstone bridge circuit which looks at the differential voltage. Look up whetstone bridge.
You can just look at one side (one output) but the change in voltage will be very small. There is also a very significant change in voltage over temperature.
You might look for a “pressure switch ” alternative.
Professionally, many years ago, I used such a sensor to design an air data computer for aircraft altitude and airspeed. A very difficult task. Lots of attention to details.

Barry

https://www.ftav.com/products/part-622-8051-004.html

Thanks for your input, It is a bridge, and yes the output has only a small change, is there something that can be used to amplify the output from 0-0.5 volts to a readable value for an arduino 0-5volt?

You need a differential amp and then have to deal with common mode voltage.
To be brutally honest, if you don’t understand a bridge and a differential amplifier, there is no simple solution.

Have a look at these devices.
https://www.digikey.com/en/products/filter/pressure-sensors-transducers-industrial/1069?s=N4IgjCBcoCwdIDGUBmBDANgZwKYBoQB7KAbRBgAYBWATgDYB2EAyuqgDhufIrrt%2B4BmSjBoxuMKoyriAugQAOAFyggAykoBOASwB2AcxABfAgCYw7KKGSR02fEVI8aVKqZDyQy1Rp0HjBAC07gg2WgCuDsSQZFQeRiYgIWQKmjhYWOFpAARYAO7aSogAFh4EdFYg2gAmqoFgFBCKKpAg3EoAngo4qmhYyAlAA

Many thanks, but I think these devices won’t give me the flexibility I need to experiment when to switch on a pump and when to shut it off. Thinking back years, I used to use strain gauges and op-amps, I will look back to my deep past.
Found something which might help, but up to date using 3 parts of LM124 so will look at that.
many thanks for you help….
Richard

You will want to use a “gage” sensor that is open ports on both sides. Expose the top of the sensor to air and the bottom to the water. This will minimize potential water corrosion to the die bond wires.
Use foam to prevent bugs from getting into the air side.