You can get some extremely good strain gauges in digital kitchen scales -
and some very poor ones. Odds are even the poor ones will be good enough.
By mechanically biasing one you get two axis (and may be able to use it
over a useful range without biasing.

I have seen various kitchen scales with poor accuracy, poor linearity and
quite often poor temperature sensitivity.

Quite some years ago (10+?) a local supermarket chain endlined some scales
with 2kg max reading and 1 gram resolution.
A test showed that a sample was able to resolve added or removed 2g test
weights (coins) anywhere across the range and that accuracy and resolution
allowed it to be used as a coin counter for as many hundreds of coins as I
has to hand. ie extremely good for what they were. Temperature shift was
essentially zero when heated to well over 50C - again, amazingly good.
AFAIR they have an extra gauge apart from the main bridge quad for
temperature compensation.
They sold for under $10 each as I recall. I and a friend bought the dozen
or so available and I've been 'using them up' ever since. I'll be sad when
I destroy the last one.

If a cheap looking low priced scale can achieve the above performance 10+
years ago a few hours spent in a few Kitchenware departments may reveal a
modern equivalent. (You'll need a source of warm air for likely candidates)=
..

You may be able to access the amplified analog signal in such devices, but
even if not adding an instrumentation amplifier per channel is affordable.




 Russell
--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.