Electric current has different characteristics, which are measured using appropriate instruments. Let's talk in more detail about these devices, or rather, find out how the ammeter differs from a voltmeter.
An ammeter is a device that allows fix the parameters of the current strength.
Voltmeter - a device for obtaining voltage readings.
So, each type of equipment is designed for specific measuring actions. Moreover, from the names of the devices it is clear which characteristics of the current they record: its strength is expressed in amperes, and voltage is expressed in volts. I must say that both devices (if we consider their arrow versions) use the same principle in their work. The readings on the scoreboard appear when the electric field and the created magnetic field interact.
But there are also details that make the difference between an ammeter and a voltmeter. They are related to the internal resistance that is available in each case. With an ammeter, it is extremely low. To ensure this condition, a resistor is provided, referred to as a "shunt" relative to such a device. The specified element is designed so that it takes the load from electricity, providing the most accurate measurement of the current strength with an ammeter.
In a voltmeter, on the contrary, the internal resistance, for which the resistor is responsible, is maximally increased, which is necessary for voltage measurements without significant distortion of the actual values.
Another answer to the question, what is the difference between an ammeter and a voltmeter, can be obtained by considering the method of connecting both devices to an electrical circuit. So, the ammeter works when connected in series. Moreover, such equipment should not be allowed to come into direct contact with the power source or current outlets. This results in a short circuit or breakage of the measuring device.
In the case of a voltmeter, the described contact is permissible. A device of this type in electrical engineering corresponds to a parallel method of connection to the section of the circuit chosen for carrying out measuring operations.
|Records current||Measures voltage|
|Minimum internal resistance||High internal resistance|
|Connected in series||Connected in parallel with circuit|
|Impermissible contact with power supply||Can be connected directly to power supply|