electrical measuring instruments – Ferrovial

Electrical measuring instruments are all the devices used to measure the magnitude of an electric current with different objectives. The values that are usually measured with this equipment are current, voltage, resistance, and power. Each is expressed in different units: amps, volts, ohms, and watts, respectively.

For the most part, the measuring instruments are portable so they can be used to make fast, accurate measurements.

What is the importance of electrical measuring instruments?

Using measuring instruments lets you record unknown data that can be compared with those that are already known. This way, you can study the characteristics and peculiarities of the electrical object being analyzed.

In everyday terms, the instruments for measuring power, intensity, resistance, and voltage make it possible to confirm the proper operation of machines and installations, as well as identifying the consumption characteristics of a certain electric energy service.

What electrical capacities do the measuring instruments measure?

Depending on what needs to be determined about an electrical circuit, different magnitudes can be measured:

1. Voltage: the difference in power that exists between two points of an element that conducts electrical current. Its unit of measurement is the volt. 
2. Intensity: the magnitude with which current circulates in an electrical circuit. Its unit of measurement is the amp.
3. Resistance: the value of a conductor versus the flow of electrons. Its unit of measurement is the ohm.
4. Capacitance: the charge storage capacity of an element in an electrical circuit. Its unit of measurement is also the amp.
5. Electrical power: originates from the combination of voltage (volts) and current (amps). Its unit of measurement is called the watt.

What are the main electrical measuring instruments?

• Galvanometer: indicates the intensity of the flow of electric current through a circuit. 
• Voltmeter: used to measure the potential difference between two points of a closed electrical circuit or the electromotive force of a battery. This instrument must have high electrical resistance so that, when it’s connected to the circuit, it does not generate consumption that alters the result and accuracy of the measurement. 
• Ammeter: measures the intensity (i.e. amps) of current circulating through an electrical circuit.
• Ohmmeter: records the ohms, or the electrical resistance, in a circuit.
• Multimeter: a meter that brings together the capabilities of the other meters: it incorporates the tools necessary to measure voltages, resistances, capacitances, etc.
• Oscilloscope: a measuring instrument and graphical display of electrical signals that vary over time. This tool makes it possible to visualize transient phenomena and facilitates the diagnosis and analysis of an electrical circuit’s operation, as well as its possible failures.
• Spectrum analyzer: measuring equipment that displays the components and spectral ranges of electrical signals coming from any wave, whether electromagnetic, mechanical, acoustic, or optical.

 How are electrical measuring instruments classified?

Measuring instruments are classified according to their function:

1. Analog: based on electromagnetic systems; when a current or voltage passes through a conductor, a magnetic field is generated that moves a needle within a magnitude scale.
2. Digital: these are the most common because they make the same measurement as analog versions but in a faster, more accurate, and more reliable way.
3. Registers: these can be either analog or digital and are responsible for recording the values being measured in a graph where the value of the magnitude is shown over a period of time.