Abstract: A unique apparatus and method are used to detect and measure movement of a valve spring pack and worm through monitoring rotation of the torque switch control post. A device for measuring the operating characteristics of a valve and its operator and the corresponding imposed valve stem load is attached to the valve operator. The apparatus provides devices for statically calibrating the operator relative to the imposed valve load and provides a device for recording traces of the improved load and associated parameters during dynamic conditions as related to the operation of the operator and valve combined. The apparatus is then used to provide diagnostic dynamic traces at any specified time in the future for the operator and valve. These future traces are used to compare with earlier traces to verify correct performance and most importantly to detect induced or impending damage, malfunctions, or maintenance requirements for the operator and valve.