Analog devices has two models: ADXL05 (range +-5 g, resolution 0.005 g, 1 g
= 9.81 m/s/s) and ADXL50.

Data sheets are on their web site.
These devices have analog, amplified output (200mV/g to 1V/g).
Typical use is for automobile airbag sensors, and I have been told that you
could find used one from auto wreckers (if the guy understand what you are
looking for!).
You can find the ADXL05 from allied electronics for 27$ (qty 1).

Bernard.

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Bernard Seront, seront@seism1.ess.sunysb.edu (MIME ok)
http://rock.ess.sunysb.edu:8080/