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RogerN RogerN is offline
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Default Digital Scales, Recalibration?


I'm wanting to make a display for load cells, good looking ones on eBay seem
to start around $150. This is a bit hard to justify for tinkering around,
especially since the load cell I want also costs around $150. As I
understand it, most digital scales work with some sort of strain gauge load
cells. This leads to the idea of getting a cheap scale (bathroom, fishing
scale, food scale) for $20 or so and using the display and electronics to
read whatever load cell I want. In order to do this I would need to be able
to recalibrate the scale. I don't mind simple X10 or X100 display (example,
display shows 200 for 2000 or 20,000 lbs) but I don't want to need a
calculator to scale and offset the reading for units conversion.

Anyone here done anything like this? Know of any cheapie scales that can be
recalibrated to different weights with other load cells? If this isn't easy
to do I'll probably just get a load cell amplifier board and use the scale
and offset pots to get the reading on my voltmeter, maybe something like
1.000 Volts = 10,000 lbs or whatever depending on the load cell.

My most immediate use will be to tension the guy wires on the antenna tower
I'm preparing to put up and later hopefully to do tests on construction of a
homemade crane. I'd like to verify/test my force calculations to keep the
design factor correct.

RogerN