The system measures two data streams. The first is from a strain gauge embedded in a rubber lifter bar to measure deflection. The strain gauge signal is converted into a frequency pulse signal, which is transmitted to a receiver via an antenna wrapped around the mill. The second data stream is from a steel plate mounted on the mill and a proximity switch that counts rotations. A receiver converts both types of data to a 4-20 mA signal and sends them to a computer.
Software produces a deflection profile for a full rotation using data from both sources.
Then the volumetric load and dynamic angle of repose are determined. There are separate charts for average profile over a number of consecutive cycles and the signal standard deviation, for charge level, and for toe, shoulder and charge angles. Calculated values are shown, such as charge level, charge angle, shoulder angle, toe angle, mill speed, average lifter deflection, and most importantly the peak level and plateau level. There is also a visual representation of the charge. The CCM solution has been a boon at Hold-McDermott.