Twenty-five years ago, tension was indicated with a 4-in. (100-mm) 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 a 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 an 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.