Weight mesurment +5v

Point an analog video camera at the scale. Digitize the video and write an image recognition system to read the numbers. Viola.

Quick thinking, i thought about this solution, the problem is that I have a need for multiple scale in multiple locations, which would need multiple cameras. Talking about the scale, where could i find / where is the type of the cheap load cell they uses for digital scales ?

How about a micro balance?

Im trying to get the level of liquid in a stainless steel keg. I dont think i can use a micro balance.

Try these guys. Not dirt cheap but US$30 ain't bad:

These are the bare sensors.

--
Rich Webb     Norfolk, VA

Sit it on a small inner tube, from an ATV tire or something. Measure the air pressure with one of those cheap ($10?) automotive or whatever IC pressure transducers.

Or hack into an electronic bathroom scale. It has the platform mechanism already done.

Hang it from a spring and measure the extension with a linear pot or an LVDT. Or measure the sprongy resonant frequency.

Lots of load cells show up on Ebay.

John

Im trying to get the level of liquid in a stainless steel keg. I dont think i can use a micro balance.

The micro balance technique. Ultrasonic?

Bob

If worse came to worst, you could buy digital scales and hack into them to get the data, or to scavenge the load cell(s)/strain gauge(s).

Otherwise, I'd google for something.

Good Luck! Rich

.

Thank for the replies, the bathroom scale scenario was indeed my fallback plan.

How about a fish scale with a linear pot.

Fish don't work for scale. Its a union thing! ;-)

--
You can\'t have a sense of humor, if you have no sense!

Depending on your definition of cheap, you might try:

Using a WII balance board (there's freeware called glovePIE) that can read/report the readings from the four load cells. The loadcells in these things are better performance than I would have thought.

Using a force-sensitive resistor (e.g. from

or WIth FSRs, a linearizing circuit is probably indicated. FSRs aren't good for static accuracy, so I wouldn't suggest their use where repeatability is important. However, the signal is large, so the interface circuit is pretty easy.

HTH,

Larry

Whats the matter with this..

Are you allowed to hack into the keg and add a sight glass?

Have Fun! Rich