Measurement is a process of gathering information from a physical world and comparing this information with agreed standards. Other ways it can be stated as the quantitative representation of information.
What are information?
Information variables which are commonly generated by processes:
- A car generates displacement, velocity and acceleration variables, and
- A chemical reactor generates temperature, pressure and composition variables.
It can be referred that the information variable is a measured variable.
Types of Measurement
- Direct Comparison
- Either with a primary standard or secondary standard
- Length with a scale, time with a clock, temperature with a thermometer etc.
- Indirect Comparison
- Use some transducing device
- Temperature with RTD/Thermocouple, Flow with orifice, height with pressure etc.
