PDA

View Full Version : strain gages



Jon Fewster
01-20-1994, 03:34 PM
Dear Scott McLean and any others interested,
I got your message: have you looked at semiconductor strain gages?
These are costly and may be hard to work with, but will measure very
small levels of strain. Also, have you looked at changing the
configuration? A full-bridge configuration should yield more signal (2.6x
one gage). This will help your problem of low signals. I don't know what
you are dealing with, but I think your range shouldn't be a problem. I
instrumented some cross-country ski poles: both aluminum and carbon fiber,
and was able to measure the strain to very low levels: small fractions of
body weight. That's what you are doing too. I used a full bridge
configuration with four standard gages for aluminum. These were
diametrically opposed with two at 90 degrees to the other two as Poisson
gages. This helps measure strain in the other direction, providing both a
better measure and more signal.
I have a few names of companies if you need them. Let me know if
you need them. Good luck.

Jon Fewster
Biomechanics Lab
Oregon State University
fewsterj@ucs.orst.edu