What's ultrasonic position meters? We refer to "positon" that is the surface position of liquid medium and solid material in the tank or equipment. Ultrasonic level meters can be devided into two major categories i.e. liquid level measurement and material level measurement: 1, Liquid level means the surface level of liquid medium. 2, Material level means the pile height of various solid materials in the form of block, particles or powder. So that ultrasonic position meter is the general term for ultrasonic liquid-level meter and ultrasonic solid-level meter.