Methods of measurement (direct measurement , Indirect measurement)

Measurement of quantity is essentially an act or the result of comparison between the amount of quantity is unknown and the standard quantity is known. Measurement is the process by which anybody can convert physical standards into a meaningful number.

The measuring process is one in which the property of an object or system under consideration is compared to an accepted standard unit, a standard defined for that particular property. For the result of the measurement to be meaningful, the standard used for comparison purpose must be accurately defined and should be commonly accepted. Also the operators used and the method adopted must be provable. 

Method of measurement

  1. Direct measurement
  2. Indirect measurement

Direct measurement:- 

  • In this method we can compare measured quantity or unknown quantity is directly  against  the standard.
  • This method of measurement sometime produce human error and hands gives accurate result.

Indirect measurement:-

  • This method of measurement is more accurate and more sensitive.
  • these are more preferred over direct measurement.
  • Mechanical Electrical and Electronic instruments.

Type of instrument's

  1. Mechanical Type
  2. Electrical Type
  3. Electronic Type

Mechanical type :-

  • This instrument used for stable and static conditions. 
  • they are unable to response rapidly to measurements of dynamic and transient condition because of having moving parts that are bulky heavy are rigid processing high inertia.

Electrical type:-

  • Electrical methods of indicating the output of detectors are more preferred than mechanical method, but they are limited time response.

Electronic type:-

  • This instrument require use of semiconductor device. The response time of the instrument are extremely small as a very small inertia of electron is only involved. The sensitivity of this instrument are also very high. Faster response, lower weight, lower power conjunctions are some of the advantages of electronic instrument.
For more understanding watch this video lecture ➽ 

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