Meaning of Ammeter
The ammeter is an instrument for measuring an electrical current in amperes.
The meter used to measure current is known as an ammeter. Current is the flow of electrons whose unit is the ampere.
Therefore, the instrument that measures current flows in amps is known as an ammeter.
The ideal ammeter has zero internal resistance. But practically the ammeter has a small internal resistance. The measuring range of the ammeter depends on the resistance value.
An ammeter can measure a wide range of current values because, at high values, only a small part of the current is directed through the measuring mechanism; a bypass in parallel with the meter carries the largest portion.
Ammeters vary in their operating principles and accuracy.
The D’Arsonval Motion Ammeter measures direct current with an accuracy of 0.1 to 2.0%.
The electrodynamic ammeter uses a moving coil that rotates in the field produced by a stationary coil. Measures direct and alternating current with accuracy of 0.1 to 0.25%.
In the thermal ammeter, mainly used to measure alternating current with an accuracy of 0.5 to 3%, the measured current heats a thermoconverter (thermocouple); The small voltage thus generated is used to power a millivoltmeter.
Digital ammeters , with no moving parts, use a circuit such as the dual-slope integrator to convert a measured analog (direct) current into its digital equivalent. Many digital ammeters are accurate to better than 0.1%.
What is an Ammeter?
Ammeters are a type of electronic measuring instrument used to assess the flow of electrical current in a given circuit.
Essentially, current flow will be measured in terms of amps.
Various models allow the device to be used to measure current quantity and speed in small and large electrical devices.
The ammeter can be used in several different fields.
The device is useful for measuring current flow through new building wiring systems, ensuring that it meets acceptable local safety codes.
Companies that manufacture electrical equipment of any kind will use this device to test products before offering them for sale.
Electricians often use this device to check for problems with wiring systems in older buildings.
In general, it can be used in almost any situation where it is possible to enter a circuit and make a measurement.
An ammeter is used to detect the flow of electrical current in a circuit.
One of the earliest working ammeters is understood to be the D’Arsonval galvanometer. This form employs the magnetic deflection process to measure amp flow.
Built with a moving coil design , the device can be connected to a circuit, and as current flows through the device, the coil begins to move within the magnetic field.
The degree of displacement and movement that the coil experiences helps determine current flow .
An ammeter can be configured to measure direct current or alternating current, and there are examples of those that are capable of measuring both types.
However, in all projects, it is important to remember that the device tends to have a relatively low resistance point.
That is, if it is connected to an incompatible source, there is a chance that the device will malfunction and possibly even short circuit.
Along with the short circuit, the action can cause permanent damage to the ammeter , as well as posing a health hazard to the person operating the device.
For these reasons, it is advisable to allow only qualified personnel to operate this tool.
The rating of the ammeter depends on its design and the type of current flowing through the ammeter.
The following are the types of an ammeter in relation to construction:
- Permanent moving coil ammeter.
- The Iron Ammeter.
- Electro dynamometer ammeter.
- rectifier type ammeter
By current, the ammeter is classified into two types :
- ac ammeter
- dc ammeter
PMMC ammeter: In the PMMC instrument, the conductor is placed between the pole of the permanent magnet. When current flows through the coil, it begins to deviate.
The deflection of the coil depends on the magnitude of the current flowing through it. PMMC ammeter is used for direct current measurement only.
Moving Amil Coil (MI): The MI ammeter measures AC and DC current. In this type of ammeter , the coil moves freely between the poles of a magnet.
When the current passes through the coil, it begins to deviate at a certain angle. The deflection of the coil is proportional to the current flowing through the coil.
Electro Dynamometer Ammeter: Used for AC and DC measurement. The accuracy of the instrument is high compared to the PMMC and MI instrument.
Instrument calibration is the same for AC and DC, that is, if DC calibrates the instrument without recalibration, it is used for AC measurement.
Rectifier ammeter: used to measure alternating current. The instruments using the rectifier instrument which converts the current direction and passes it to the PMMC instrument.
This type of instrument is used to measure the current in the communication circuit.
The instrument that measures direct current is known as the DC ammeter and the ammeter that measures AC is known as the AC ammeter.