Maybe some of these will help:
http://www.ebay.com/sch/i.html?_sacat=3D0&_nkw=3Doil%20sensor%20pressure&_s=
op=3D15

Cheers,
Mario


At 10.57 2012.06.13, you wrote:
>Hi,
>
>I'm constantly having trouble with pressure switch of a water pump,
>which is supplying water from a well for a house and garden. Setup is
>far from optimal, and seems like normal, membrane-activated switches
>are having trouble with this. I am sure there are better switches
>available somewhere, but I had an idea to build one by myself, using a
>PIC. That way I could have better control of ON and OFF pressures, and
>hysteresis, probably also some kind of dynamic self-adjusting, to cope
>with completely different situations of supplying just home, vs
>supplying water for garden. Soft start of a pump motor could be
>implemented easily too.
>
>Any ideas what cheap pressure sensor could be used? Sensor has a
>direct contact with water.
>Some kind of a digital output would be best, but i can live with
>analog signal too.
>Best if that sensor is widely available, that is, used in some
>consumer equipment.
>
>Somebody recommended to use oil pressure sensor from a car, that has
>continuous-signal sensor, not just a pressure switch, but I do not
>have an exact car model that uses this kind of sensor.
>Probably sensor, designed to contact with oil, would not live very
>long with water, but it's ok to replace it sometimes if it's cheap
>enough.
>
>I'm interested in pressures between 1 and 6 bar, or so.
>
>--=20
>KPL
>--=20
>http://www.piclist.com PIC/SX FAQ & list archive
>View/change your membership options at
>http://mailman.mit.edu/mailman/listinfo/piclist

--=20
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View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.