Dynamic analysis of plumb-line-type liquid level measurement system

This category of continuous level sensors is related to the float type. An angular-position transducer is used to indicate the number of turns of a drum as a plumb line wound on the drum is unwound until a weight (for solids) or a float (for fluids) touches the surface. When this occurs the plumb line loses tension, a tension sensor (force transducer) detects the loss in tension and sends a signal to a direction-changing device, that controls a drum drive motor. Operating variables play a major role in determining accuracy and repeatability requirements. The paper presents a dynamic analysis and identification of the sensor system to increase static and dynamic accuracy.