Bill:
I agree those furnaces are a little big to calibrate sensors with! How long
does it take to stabilize a big temperature change, anyway? Hours, I'll
bet.
The sort of simulation you mention should be easy enough to do, provided you
have an accurate and stable microvolt source. Leeds and Northrup used to
make a "potentiometer"-- which actually was a lot more than that. You could
read and simulate all kinds of TCs with it. All you needed was the TC
voltage tables. Worked off a Wheatstone bridge.
I have a modern digital version (from Omega-- can't remember who actually
makes it). Pretty expensive.
That's a good idea you had. I could find out quite a bit about the field
amps without setting-up very much equipment. Now if I could just get the
darned datalogger harness.
BTW-- you can get some fairly cheap little TC simulator boxes, but i think
they typically only give you one voltage/ temperature point, for one kind of
TC. I used to have one or two (came packaged with other equipment), but I
don't remember ever trying one or knowing how they work; I always had
something to use that I liked better.
Russ, #1226B
-----Original Message-----
From: Bill Pokey Bennett [mailto:bennevl@bellsouth.net]
Sent: Wednesday, May 07, 2003 4:19 PM
To: Russel Mack; Keith Turk; Nigel Shaw; land-speed@autox.team.net
Subject: Re: Quick Data Connectors
Russ,
yeah maybe I should have mentioned how big our heat treat furnaces are. I
think last time I measured they were close to 70 feet long. We use them to
mass treat large numbers of valve lifter rollers and tripod bearings.
Without proper equipment it would be impossible to accurately calibrate the
data acq. I was just thinking about establishing some sort of base line to
go by. Granted he has already been running this system for some time, but it
wouldn't hurt to check it once a year at least. Oh I can hear it now. You
would know when a sensor was reading bad cause of the bad data collected.
Yeah but that is one run wasted the data is useless and a motor only has so
many runs in it right Keith.
I was thinking more along the lines of simulating the analog inputs along a
series of points to verify the A/D conversions. Just a simple test to
verify everything was normal. Hey wait a minute what is normal?
Bill
"Garbage in equals Garbage out"
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