1 June 2020

Ammeter | Definition | Symbol | Formula | Type | Advantages | Uses

What is ammeter?


The meter uses for measuring the current is known as the instrument ammeter. The current is the flow of electrons whose unit is ampere. Hence the instrument which measures the flow of current in ampere is known as ampere meter or ammeter.

The ideal ammeter has zero internal resistance. But practically the ammeter has small internal resistance. The measuring range of the ammeter depends on the value of what resistance we have to set.

Symbolic representation:




Types of ammeter:


Following the type of ammeter regarding to construction:

  1. Permanent moving coil ammeter
  2. Moving iron ammeter
  3. Electro dynamometer ammeter
  4. Rectifier type ammeter 

1. Permanent moving coil ammeter


It is also called the PMMC instrument the conductors are placed between the pole of the percent magnet. When the current flows through the coil, it starts defecting. The deflection of the coil depends on the magnitude of current flows through it. This ammeter used only for the measurement of the direct current. 

2.  Moving coil ammeter

It is also called as the MI type of matter. The MI ammeter measure both the alternating and direct current. In this type of ammeter, the coil freely moves between the poles of a permanent magnet. When the current passes through the coil, it starts deflecting at a certain angle. The deflection of the coil is proportional to the current passes through the coil. 

3. Electro dynamometer ammeter


It is used for the measurement of both AC and DC. The accuracy of the instrument is high as compared to the permanent moving coil (PMMC) and Mvoinf coil (MI) instrument. The calibration of the instrument is the same both for AC and DC. If DC calibrations the instrument then without recalibration, it is used for AC 
measurement. 

4. Rectifier ammeter


It is used for measuring the alternating current. The instrument using the rectifying instrument which converts the direction of current and passes it to the PMMC instrument. Such a type of instrument is used for measuring the current in the communication circuit.

Application of ammeter:

  • The application of this device will range from school, colleges or to industry.
  • These are used to measure the current flow in the building to ensure that the flow is not too low or too high.
  • It is used with a thermocouple to check the temperature.
  • These current flowing through the coil produces the desire deflecting torque.
  • Electricians frequently use these devices to check the faults of the circuits in the building.
  • It is used in manufacturing and instrumentation companies to check the functionally of the devices.
  • This instrument is used to measure current in the circuit.
  • It is always connected series in the circuit and carries the current to be measure,
  • It is used with a thermocouple to check the temperature.
For detailed information>> Live use of an ammeter 


Advantages and disadvantages of ammeter

Advantages of ammeter:

  • It is strong, portable.
  • It does not dependent on the earth's magnetic field.
  • It could be made very accurate.
  • An ammeter is used to measure the magnitude of electric current in an electric circuit.

Disadvantages of ammeter:

  • It is heavy.
  • It needed multiple heavy meters to measure a different range of amperage.
  • It could not store data.

For detailed information>> Advantages and disadvantages of ammeter 

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