20 years ago, tension was indicated with a 4” (100mm) analog meter on the operator console. These meters were rugged, accurate to about 1%, and provided a nice degree of damping or filtering.
Today, the analog meter is rare, replaced with a number or bar on the operator console. The numeric tension indication is not as useful as a bar display. The bar is not useful unless it updates 10 to 25 times per second. Check your tension displays. I expect many of you have a numeric display with 1 second update and enough filtering in the load cell amplifier and software to stabilize the Titanic.
A better display is a trend. Again we like 10 updates per second or better.
Since the sky is the limit today, why not a tension vibration spectrum which could relate tension variations to particular rollers or the tuning of the tension regulator. This requires a FFT of the load cell feedback and would be very valuable to maintenance. To be useful, the FFT must take good readings from 100 Hz down to 1 Hz.
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President. Designated Consulting Engineer with Professional Engineers Ontario (PEO). KlassENgineering was incorporated in 1999. Clarence applies 31 years in the Pulp and Paper industry to solving problems with drives for web handling. He has 10 years experience as a drives engineer with GE Canada and 10 years experience with Opcode Systems Inc., a PLC and Drives Systems Integrator. Much of Clarence's experience was gained in onsite installation of new equipment and troubleshooting of existing equipment. KlassENgineering performs Pre-Start Health and Safety Reviews as required by the Ontario Ministry of Labour.
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