Chris Cox wrote:

> (Actually, no object rests in a centrifugal field on more than 3.

 The three point lesson is for non-deformable objects, most of the oven
racks I know deform like crazy when respectable loads are placed on
them.

I think your strain gage is possibly a very good choice, but I would
place one near each of the four corners of the rack so they are the ONLY
possible contact points. Then regardless of where the load is placed the
total weight is the sum of the loads on the four strain gages (even if
only three are making contact).

I also assume a thermometer is present to measure the temperature near
each of the strain gages to calibrate them vs temperature.

Unfortunately the original post did not specify whether this mechanism
had to fit in an existing oven or the oven could be modified
appropriately to handle the measuring apparatus.

If the rack is removed and placed on another level within the oven, is
the measurement expected there as well? Is this going into a commercial
product where it will be used and abused, or a one-off for some
engineering study that can be handled "gently"? Without knowing some of
these answers, a true solution is unobtainable.

David W. Gulley
Destiny Designs

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