The ultrasonic sensor sends an ultrasonic pulse from the bottom of the clamp and the signal is reflected back to the sensor off the bottom of the plunger. The sensor measures the return time and gives an accurate position reading for the clamp. Set up the desired clamping and unclamping ranges using the master control system included in the two sensing packages. During operation the master control will send a go or no-go signal to the machine depending on the data received from the sensors. No-go signal will prevent damage to the part or machine due to a failed or damaged clamp.