The Multimeter it’s a device which is used for measurement of electrical quantities. These instruments can be used with alternating current or with DC.
Also know as tester or multimeter, the multimeter can measure passive quantities (such as endurance) or active quantities (such as tension). There are the analog multimeters and the digital multimeters.
Multimeters use galvanometers, which can record the intensity of very small electrical currents. The galvanometer completes a certain electrical circuit for the measurement of the various quantities.
Due to its characteristics, the multimeter can work in different ways. What ohmmeter, you are able to measure the resistances in ohms. What voltmeter, is used to measure the potential difference between points in an electrical circuit. Another modality of the multimeter is its action as ammeter, measuring the intensity of the currents.
In the ideal plane, a multimeter as a voltmeter does not extract current and has infinite input resistance. Similarly, as an ideal ammeter, the multimeter does not register voltage drop and has zero input resistance. The characteristics of the real equipment, however, are different.
In some cases, multimeters may offer additional features. Used to test telephone lines, check the electronic circuits of a car or function as an oscilloscope are some of the possibilities.
On the other hand, it is important to note that, as a safety mechanism, multimeters usually have one or two fuses. This allows that, if there is an excess of current, the appliance is not damaged.