Level meters these devices continuously measure the volume of liquid, powder, or granulated materials. (This is also referred to continuous level meter, liquid meter, or powder meter.)
Although a level switch can detect the presence of material at a certain point, a level meter outputs a reading of the total liquid volume in a tank, usually from 0 to 100%.
So, a level meter can monitor and control the volume in greater detail than a level switch. The level meter usually outputs its reading as a small current of 4 to 20mA.
(4mA represents 0%, 20mA represents 100%, and 12mA represents 50%,)