Define physical quantity ?
Any quantity which can be measured is known as physical quantity.
Define Measurend ?
A physical quantity which is being measured.
Sensors are devices which transform one physical quantity to another physical quantity.
Define Transducers ?
A device which provides a usable output in response to a specified measurend.
Define Active Instruments ?
An active instrument uses an auxiliary energy source to produce the desired output signal.
Define Passive instruments ?
A passive instrument can convert physical or chemical properties into another property without the aid of an auxiliary source.
Define Primary Instrument ?
A primary instrument is a scientific instrument,which by its physical characteristics is accurate and is not calibrated against anything else.
Define Secondary Instrument ?
Secondary instruments must be calibrated against a primary standard.
What is the difference between measured value and true value?
Measured Value - Any value or any reading calculated from measurement system or measuring instrument is known as measured value.
True value - Any value calculated from rated values is known as true value.