Practical speed and elongation measurement, using encoders, for a Temper mill

Speed and differential speed measurements are necessary for almost all of manufacturing steel processes. Use of incremental rotary encoder is the cheapest method for this purpose. Classical theoretical algorithms are analyzed in terms of error and sampling time. These methods are used for a Temper mill real case, showing the practical limitations in both speed and differential speed. A new differential speed measurements algorithm is introduced, showing how to solve eccentricity problems, and that a bad processing but not slippage is the source of observed false elongations peaks. Thus, incremental rotary encoder with a proper processing algorithm can offers higher accuracy than other more expensive non contact speed sensors.