Level measurement refers to the process of determining the depth or height of a substance, such as a liquid or granular material, within a container or vessel. Flow measurement involves determining the rate at which a fluid, such as a liquid or gas, is flowing through a system. Pressure measurement is the process of determining the force being exerted on a surface by a fluid or gas, which is typically measured in pounds per square inch (psi) or pascals (Pa). Temperature measurement involves determining the degree of hotness or coldness of an object or substance, which is typically measured in degrees Celsius (°C) or Fahrenheit (°F).