On Sun, 7 Apr 2013 11:04:41 -0700 (PDT), "
wrote:

On Apr 7, 10:06*am, Ignoramus32392 ignoramus32...@NOSPAM.
32392.invalid wrote:



So, now I always know the main cylinder pressure. I am going to weigh
a few things of known weight (I do have a 10k floor scale, so it not
hard to come up with known weights). Then I would write up a table of
weight/pressure values and run a linear regression, then I would print
out a table with these values. That way we'll know for sure what
weighs how much.

I did hook all of that up yesterday, but did not yet play with this
due to lack of time, but I plan on doing so shortly.

i

I would be interested is knowing how linear the weight / pressure is.
Where I worked they have a sling test tower where they proofed and
certified weight handling gear. I am pretty sure they ignored any
possible non linear effects and just multiplied the pressure by the
area of the piston. And I have always wondered how accurate that
approach was. Have also been involved with making small weight scales
to go under each wheel of a race car to set up the suspension. There
of course one does not need absolute weight.

We low-buck racers used a bathroom scale and a 2 x 8 with a fulcrum. A
mess to set up, but it worked.

And I made my own tire-temperature gauge with a 1N914 diode for a
sensor and an op-amp and analog gauge. Accurate to within a degree or
so, and dirt cheap.

1N914s, unlike thermistors, are linear as hell and they respond in
about one second to tire temperatures. Leads must be short, however.

--
Ed Huntress



Dan