SI unit in Instrumentation
2 base units are used in Instrumentation Level and Temperature. Flow and pressure are derived units.
Pressure = Force / Area.
Unit of pressure is Pascal and it is the force of 1 newton applied to the area of 1 square meter.
Pa = N / m2.
Pressure is the quantity very much used in instrumentation. Pascal is a very small unit of pressure. So practically a 100000 times greater unit is used and it is called Bar.
1 bar = 100000 Pa.
In instrumentation other than pressure three more quantities are used and they are
Temperature, Level, and Flow.
Temperature is one of the 7 base quantities of SI system of measuring units.
The unit of temperature is kelvin. For practical use another unit is used called Celsius.
Celsius is Kelvin minus 273.16 .
Flow rate is the volume or mass passing through a certain section in a unit of time. Flow is expressed in kilograms per second or liters per second or their multiples.
Level is the height of a liquid in container.It is measured in meters or percentage of a maximum level.