How do you make a strain gauge device that measures the strain (change
in length) of a metal band by clamping the gauge device onto the metal
band. The gauge would be an analog bridge strain gauge that would
have to have pads that allow them to be clamped on the metal band, but
the material that the gauge device was made of would have to have
little effect on the total resistance to elongation of the band, since
the band strain vs. force is what is being measured.

I know I could glue a strain gauge on the band itself to do the
measurement, but I want to be able to mount and unmount the strain
gauge on different bands.

The actual thing I am measuring is the tension in a bandsaw blade. I
found I could buy a mechanical strain gauge to do the measurement, but
find that I can buy a used strain gauge meter for much less and if I
can make a gauge, I will have a strain gauge meter for use in other
applications. Also, I believe it could potentially be more accurate
also.

uk.d-i-y

eganders wrote:
How do you make a strain gauge device that measures the strain (change
in length) of a metal band by clamping the gauge device onto the metal
band. The gauge would be an analog bridge strain gauge that would
have to have pads that allow them to be clamped on the metal band, but
the material that the gauge device was made of would have to have
little effect on the total resistance to elongation of the band, since
the band strain vs. force is what is being measured.

I know I could glue a strain gauge on the band itself to do the
measurement, but I want to be able to mount and unmount the strain
gauge on different bands.

The actual thing I am measuring is the tension in a bandsaw blade. I
found I could buy a mechanical strain gauge to do the measurement, but
find that I can buy a used strain gauge meter for much less and if I
can make a gauge, I will have a strain gauge meter for use in other
applications. Also, I believe it could potentially be more accurate
also.

uk.d-i-y
I've seen somewhere recently references to using a cheapo digital
caliper to do this job .
Pause for search.........
Here is the link. I think the forum is visible to non members.

http://www.ukworkshop.co.uk/forums/v...ic.php?t=12784

HTH

Bob

On Apr 8, 6:10*pm, Bob Minchin wrote:
eganders wrote:
How do you make a strain gauge device that measures the strain (change
in length) of a metal band by clamping the gauge device onto the metal
band. *The gauge would be an analog bridge strain gauge that would
have to have pads that allow them to be clamped on the metal band, but
the material that the gauge device was made of would have to have
little effect on the total resistance to elongation of the band, since
the band strain vs. force is what is being measured.

I know I could glue a strain gauge on the band itself to do the
measurement, but I want to be able to mount and unmount the strain
gauge on different bands.

The actual thing I am measuring is the tension in a bandsaw blade. *I
found I could buy a mechanical strain gauge to do the measurement, but
find that I can buy a used strain gauge meter for much less and if I
can make a gauge, I will have a strain gauge meter for use in other
applications. *Also, I believe it could potentially be more accurate
also.

uk.d-i-y

I've seen somewhere recently references to using a cheapo digital
caliper to do this job .
Pause for search.........
Here is the link. I think the forum is visible to non members.

http://www.ukworkshop.co.uk/forums/v...ic.php?t=12784

HTH

Bob- Hide quoted text -

- Show quoted text -

Ah Ha! I did the same thing with a 6 inch dial caliper, but the
digital caliper does go down to .01 mm. It may not be super accurate,
but it is more precise than my dial caliper. I can get about .03 mm
over a 127 mm range, so I ge about 7 KPSI. That is pretty good and
maybe good enough for what I am after. Thanks!!

On Tue, 8 Apr 2008 11:52:35 -0700 (PDT), eganders
wrote:

I know I could glue a strain gauge on the band itself to do the
measurement, but I want to be able to mount and unmount the strain
gauge on different bands.

So do it. Bond your gauges onto a steel bar, clamp each end to the
untensioned band (just little G clamps are adequate), then tension.

Stress (force/area) will be different, but the strain (elongation) will
be identical. As the gauge bar is so much stiffer than the blade,
rigidity (and strain variation) just isn't a problem. Just watch out for
not squishing teeth with the clamps, yet still avoiding slip.

--
Cats have nine lives, which is why they rarely post to Usenet.