Development of liquid level measurement technology: A review

Depending on various applications, the process control industry uses liquid-level sensors of different principles. Due to the dynamic nature of liquid such as water, wastewater, petroleum etc., and characteristic of storage tank, the measurement is difficult and it violate the accurate measurement. Instances of level measurement and control failure lead to tragic and costly consequences. Selecting the accurate level measurement technique for a particular application is a daunting task in the face of many options and limitations. Hence, this paper reviews liquid level measuring instruments used in the past 11 years. Both the contact and non-contact measurement are discussed, and their development on measuring liquid level is also covered in this review paper. From the study, it is clear that ultrasonic sensors are most widely used for liquid level measurement with high accuracy while neglecting the drawback of the echo inside the tank.