Experimental Physics and
Industrial Control System

Steve Hunt <[email protected]> · Thu, 27 Apr 2000 08:30:06 +0200

Would anyone be willing to  comment on the accuracy and resolution achieved with
these different solutions proposed  for thermocouple measurements ?

Steve Hunt

Steve Lewis wrote:

> At 5:24 PM -0500 2000/04/25, Porter, Rodney wrote:
> >I need to monitor 24 thermocouples.  Can someone suggest EPICS supported
> >hardware for this application.
>
> Our method of choice here is to hook them directly to Allen-Bradley
> Flex-I/O modules which are deployed close to the sensors.  These 8-channel
> units handle all known types, and have cold-junction compensation
> and a calibration procedure.  The unit is model IT-8.
>
> Three IT-8 units can be combined in a small DIN-rail stack. (And they can
> be mixed with other units for handling pressure, flow, whatever, in a nicely
> distributed manner.)  With adaptor and power supply (but not including
> 6008 scanner) using typical discounts, it would cost about $3700
>
> They can connect to the IOC either directly to the 6008 scanner (we are
> just finishing device support) or via any A-B series PLC (in which case
> the generic PLC device support already works).
>
> We much prefer this "raw sensor" approach here to the rack-mounted/
> multiplexed/bells-and-whistles/RS-485-protocol-from-hell style of the
> typical catalog instrument.  Your mileage may vary...
>
> _____________________________________________________________________
> Stephen A. Lewis                        | [email protected]
> Mail Stop 71-259                        | http://www.lbl.gov/~salewis
> Lawrence Berkeley National Laboratory   | Tel: +1.510.486.7702
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System