Category: Electrical & Electronics Measurements
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Magneto-Optic Current Sensors for High Voltage, High Power Transmission Lines
One of the key challenges in measuring the electrical current in high voltage, high power transmission lines, is that of measurement circuit isolation. One way of measuring heavy 60 Hz currents in a conductor is through the use of a current transformer. A current transformer typically consists of a number of turns of wire wound…
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Digital Voltmeters: Basic Features, Operation & Applications
The digital voltmeter (DVM) displays measurement of ac or dc voltages as discrete numbers instead of a pointer deflection on a continuous scale as in analog instruments. A digital voltmeter basically consists of an analog-to-digital converter, a set of seven-segment numerical displays and the necessary BCD-to-seven-segment drivers. A digital voltmeter is a versatile and accurate…
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Sweep Frequency Generator: Function, Features & Applications
Function & Features of a Sweep Frequency Generator A special type of signal generator which generates a sinusoidal output whose frequency is automatically varied or swept between two chosen frequencies is referred to as sweep frequency generator. One complete cycle of the frequency variation is termed as a sweep. The rate at which the frequency…
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Digital Multimeter: Principle of Operation and How it is used
A Multimeter or volt-ohm-milliammeter (VOM) is an instrument used to measure current, voltage, and resistance. It can be used for measuring dc as well as ac voltages and currents. The two common types of multimeters include the analog multimeter and the digital multimeter. Analog multimeters employs a moving pointer mechanism that swings a long a…
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Megohmmeter: Function & Operation
The megohmmeter or megger is a portable deflection instrument widely used to check the insulation resistance of electrical cables and equipment. In other words, a megohmmeter can be described as a high resistance measurement instrument. The instrument has a constant high-voltage source, normally produced by a hand-cranked generator. The voltage may range anywhere between 100…
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Standards Used in Measurements & Their Classifications
For anyone performing a measurement using a particular instrument, it usually matters to know whether the instrument is calibrated or not. Calibration is required, along with precision, to enable accurate measurements to be made. Calibration means observing the instrument’s performance when measuring a standard of some kind. A standard is a physical representation of the…
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Oscilloscopes: Function, Features, Applications & Selection Guide
The Function of an Oscilloscope An oscilloscope is an electronic instrument that presents a graphical display of its input voltage as a function of time. It is important to note that oscilloscopes only measure voltages not currents or resistances however it is possible to convert quantities such as current, strain, acceleration, pressure and so forth…
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Pulse Generator: Function, Operation & Applications
The Function of a Pulse Generator A pulse generator is an electronic instrument used to generate pulses for use in different types of electronic applications. Pulse generators are mainly utilized for production of pulses that are used to test applications that involve digital circuits like shift registers, counters, and so forth. Operation of the Pulse…
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Function Generator: Features & Applications
Features of Function Generators A function generator is a signal source that can produce different types of waveforms as its output signal. The most common output waveforms are: sine waves, square waves and triangular waves. Furthermore, some function generators also produce sawtooth, pulse and non-symmetrical square waves. A typical frequency range for function generators is…
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How to Calibrate an AC Ammeter & an AC Voltmeter
An instrument calibration is performed by comparing its reading with that of a more accurate instrument when both instruments are measuring the same quantity. In this case, the more accurate instrument is employed as a standard for comparison purposes. To calibrate ac ammeters and ac voltmeters, ac supply and an ac standard instrument must be…