In this PPT contain basics of measurements and measuring instruments

3. What is purpose of measurement
 The purpose of Measurement system is to present
measured value to Numerical value
Example –
1) Energymeter - Measured in 15 Kwh
2) Temperature - Measured in 32 degree Celsius

4. Define :- Measurement
 “ It is define as to measure the unknown quantity is
compared with predefined standred values with
significants unit is called as measurements “

5.  Measured Value :- Any value or reading calculated from
measuring instruments is known as measured value
 True value :- Any value calculated from rated value is
known as true value

6. For Example :-
ELECTRIC
MOTOR
(1500 RPM)
TACHOMETER
(1490 RPM)

7.  Define Error :- Diffrence between true value and
measured value called as error
or
 It is define as the deviation of measured value from true
value

8. ANALOG MEASURING INSTRUMENTS
Voltmeter (V) :- Measuring in voltage (V)

9. AMMETER (A) :- MEASURED IN AMPERE(A)

10. POWER (P) :- MEASURED IN WATT (W)
POWER (P) = VOLTAGE (V) * CURRENT (I)

11. ENERGY (E) = MEASURED IN KILOWATT HOUR (Kwh)
ENERGY (E) = POWER(P) *TIME (T)

12. DIGITAL INSTRUMENT (MULTIMETER)

13. Digital Clamp on Meter

14. MEASUREMENT
 Classification of Measuring Instruments
 Electrical instruments may be divided into two categories,
that are;
 1. Absolute instruments,
 2. Secondary instruments.

15. Absolute instruments or Primary
Instruments:-
 Those instruments read the quantity under measurement
indirectly ie- interms of deflection ,meter constant
 Example – Galvanometer, wattmeter and current
balancing meter

16. Secondary instruments
 Those instruments read the quantity under measurement
directly
 Example – Ammeter , voltmeter

17. Secondary Instruments further classified as
 1) Indicating Instruments
 2) Recording Instruments
 3) Integrating Instruments

18. INDICATING INSTRUMENTS
 These instrument which indicate the Magnitude of
quantity being measured is called as indicating
instruments
 Example – Ammeter , Voltmeter

19. Recording Instruments
 These instrument which gives a continues record of
variation of quantity being measured is called as
Recording instruments
 Example – X-Y Recorder , Strip chart recorder.

20. Integrating Instruments
 The integrating instrument measure the total electrical
quantity supplied by the circuit in given interval of time
 Example – Watt hour meter , Energy meter.