Cheap pressure sensor

[Dan Ritter]

I was wondering if there was a cheap way to messure pressure. Perhaps
up to 50 psi. I have this cheap digital tire pressure sensor that seems
to work good. I'm sure they didn't put a $50 or $100 pressure sensor in
it. I don't need really good accuracy. Within a couple % would
probably be fine.

Any ideas? Thanks

 

[Richard]

How many total, will you need?
If you need 300 or more I can help

Richard

 

[Dan Ritter]

How many total, will you need?
If you need 300 or more I can help

Richard

No. I'm afraid it's just for a few small projects. Is that what the
tire pressure sensor has? If you buy thousands you can get the sensors
for a few dollars instead of $100?

The best idea I've had so far is I've noticed some surplus electronics
places have had these sensors for sale. Right now they just show sold
out though.

Like I said. I don't need really good accuracy. Even within 10% I
would be willing to accept if it was a cheap thing. Basically I just
don't want my device to overpressure too much.

I wouldn't mind hearing what you have. Mostly just curiousity. I don't
think I could afford 300 of them.

I hope someone has an idea that will work.

Thanks

 

[BEVERNON]

Subject: Re: Cheap pressure sensor

From: Dan Ritter [email protected]
Date: 1/21/05 2:08 P.M. Eastern Standard Time
Message-id: <drcId.39734$06.1656@clgrps12>

No. I'm afraid it's just for a few small projects. Is that what the
tire pressure sensor has? If you buy thousands you can get the sensors
for a few dollars instead of $100?

The best idea I've had so far is I've noticed some surplus electronics
places have had these sensors for sale. Right now they just show sold
out though.

Like I said. I don't need really good accuracy. Even within 10% I
would be willing to accept if it was a cheap thing. Basically I just
don't want my device to overpressure too much.

I wouldn't mind hearing what you have. Mostly just curiousity. I don't
think I could afford 300 of them.

I hope someone has an idea that will work.

Thanks

Try cooper instruments. Do a search for 'force sensor' and you will find
several companies who make force sensors and pressure sensors. About 10
dollars per.
Brad

 

[Si Ballenger]

I was wondering if there was a cheap way to messure pressure. Perhaps
up to 50 psi. I have this cheap digital tire pressure sensor that seems
to work good. I'm sure they didn't put a $50 or $100 pressure sensor in
it. I don't need really good accuracy. Within a couple % would
probably be fine.

Any ideas? Thanks

Go to WalMart ande look in the auto section for digital tire
pressure gages. I think I've seen them there in the ~$10 range.
I'd also look in the "dollar" type stores for them. The below
link might also be of interest (maybe free sample).

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MPX4250&nodeId=01126990368716

 

[Gary Helfert]

www.mouser.com, 0-100 psi, $15 each or $13 in batches of 10.

 

[ALBERT C. GOOD JR.]

Dear Gary

One method that might work depending how much trouble you are willing to put
into the project would be to use a oil pressure sender device from as used
in certain automotive engines.

These devices used to use carbon or graphite buttons compressed by a
diaphragm to measure the oil pressure of such a engine.

Carbon has the interesting characteristic of changing resistance when paced
under mechanical pressure. This characteristic was and probably still is
used in the transmitter of certain telephone mouth pieces and microphones.

Usually in the case of engine oil pressure the unit is simply in series with
the battery and the measuring gauge. However it is conceivable that you
might be able to arrange several of these into a bridge circuit for better
accuracy.

If you are looking for quick and dirty, then a trip to a plumbing store to
buy a bourdon type presure gauge, might be the most direct method of
achieving your goal.

Albert