b) Deadband correction allows the motor to break free of the static friction. Once moving freely the torque required to ‘stick’ the motor is determined by the lower kinetic friction. Generally this means that the motor can move slightly slower than the static friction minimum speed, but not the kinetic friction minimum speed.
c) Calibration is a process where instrumentation outputs are related to inputs. These results are then used later to relate measurement equipment outputs with actual phenomenon. For example, in the laboratory, tachometers are calibrated by turning them at a steady speed. The speed is measured with a strobe tachometer and the voltage output is also recorded. These are then used to make a graph relating voltage and speed. Later the strobe tachometer is not used and the voltage output of the tach. is used to calculate the speed.