Powered by The eurotherm   AMS2750 standard is very important for metals treating plants that are participating in NADCAP industries. Specifically, thermal uniformity surveys (TUS) with the appropriate reporting is often an expensive but necessary requirements for plants that must prove compliance to NADCAP standards.  For a metals treating plant with 130 furnaces, a team of engineering, maintenance, and quality had a major challenge performing the surveys quarterly, maintaining the equipment, and producing the appropriate reports.

Neal Systems had originally presented this plant with Invensys Eurotherm’s Chessell 6000 series recorder with TUS reporting package.  The plant was initially elated, but upon further testing, found that they needed even more customization and automation than the package offered.  For instance, some furnaces were programmed around degrees Fahrenheit, while others were degrees Celsius.  There were approximately 40 different furnace TUS test setups, with anywhere from 6 to 40 thermocouples.  The types of thermocouples differed significantly, including S, N, T, and K.  Some of the furnaces required door tests, where the supplier wanted to verify the response of the furnace to doors being opened and closed.  The whole system would have to be highly mobile, simple to use for the maintenance team, accurate enough to meet the extremely tight accuracy levels required by the AMS2750 standard, and highly automated from selecting a furnace to printing a final TUS report.

A Eurotherm distributor, Neal Systems, was able to produce a design based around the Invensys Eurotherm 2550 series control and I/O package in a mobile thermocouple data collector coupled with an Invensys Wonderware SCADA screen with historian for furnace test interface and report printouts.

When the maintenance team needed to run a test report, they would select from one of two “thermocouple pods” that most closely matched the type of thermocouple inputs needed for that test run.  After connecting all of the test thermocouples to the appropriate pod, they would then take a laptop loaded with the custom Wonderware interface, and connect to the pod.  The interface would allow them to enter all of their pertinent data to the run, select a pre-configured “furnace characterization” (one for each of the 130 furnaces, with the correct number and type of thermocouples along with anything else special for the furnace), and then start their run.  From a quality control standpoint, the custom interface included intelligence to show which pod was active (and which one was not), which thermocouples were active, and compare that to the furnace characterization in question to verify everything was a match.  Preconfigured alarms would provide warning at each level should any of the thermocouples show a reading outside of the acceptable band.  A custom calibration interface provided the ability to check and recalibrate all channels quarterly to ensure accuracy standards are maintained.