Subject: RE: LOAD CELL SPARES
Date: Mon, 3 Dec 2001 17:16:28 -0600
From: "Kaufman, Tom" <Tom.Kaufman@mts.com>
To: "'pcastald@atc.army.mil'" <pcastald@atc.army.mil>
CC: "Larson, Rod" <Rod.Larson@mts.com>

Pat:
The MTS calibration provides traceablility to NIST since we are using
the MTS electronics, cable and transducer.  For you to get an equal
calibration at your site, you would need to bring the force standard
cell  to the bridge testing frame and fixture it at the actuator,  or
else bring the electronics and cable to a load frame where the force
standard is located.  Either way is a lot of work.  There are alignment
inaccuracies if you try to fixture something at your test frame that
would make it very difficult to get repeatable results.

If you try to use the mv/v listed on the Interface calibration sheets,
and then use the calibration factor(Gain) on the 497.22 dc conditioner
electronics screen, you can be close (maybe 2% more or less), but you do
not have a traceable calibration.  (The 497.22 dc Conditioner module
used for load cells, has a x500 amp and a x10 amp.  These are nominal
numbers, but they are not calibrated, or traceable.  The 497.22 is an
analog conditioner.)

MTS Service department offers calibration service, where you can send
your load cells, and they will provide the calibration and certificates.
You need to identify the electronic conditioner(497.22), and cable
length that you have on your machine(235 feet). They can be reached by
calling MTS HELPLINE, on 1-800-328-2255.
Tom Kaufman
> -----Original Message-----
> From: pcastald@atc.army.mil [SMTP:pcastald@atc.army.mil]
> Sent: Monday, December 03, 2001 4:32 PM
> To:   Kaufman, Tom
> Subject:      LOAD CELL SPARES
>
> Tom,
>
> There is a Bridge Test Working Group that I've been briefing on the
> status
> and operation of the BCS.  They are worried about having spare load
> cells.
> They want me to buy 4 spare load cells so that in the event of a load
> cell
> problem I could change them and continue testing.  What's the easiest
> way to
> do this and get them calibrated?  I could look into getting
> calibrations
> done here at APG.  How much more accurate is the MTS Calibration
> compared to
> the factory Cal?
>
> -Pat
