Category: Electrical & Electronics Measurements
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Features and Applications of Instrument Transformers
Instrument transformers are used in the measurement of voltage, current, energy, and power in ac circuits. The main reasons why instrument transformers are employed in measurements are: In power systems, the levels of currents and voltages handled are very high, and therefore direct measurements with conventional instruments is not possible without compromising the operator safety,…
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Power Measurement in AC Circuits (Single-phase & Polyphase Systems)
Introduction to AC Power Measurement In alternating current circuits, the instantaneous power varies continuously as the voltage and current varies while going through a cycle. In this case the power at any instant is given by: p(t) = v(t) x i(t) Where, p(t), v(t) and i(t) are the values of instantaneous power, voltage and current…
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Performance Characteristics of Digital Measurement Instruments
In this article, we discuss the performance characteristics of digital instruments i.e. Resolution Accuracy Linear errors Settling time Temperature sensitivity Monotonicity Resolution This is defined as the smallest increment in voltage that can be discerned. It is the reciprocal of the number of discrete steps in the Digital to Analog (D/A) converter input. Resolution depends…
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Key Instruments Used By Electronics Engineers
Multimeter This is also called volt-ohm-milliammeter (VOM). It is a general purpose instrument having the circuitry and switching arrangement for measuring ac/dc voltage or ac/dc current or resistance. It is simple, compact and portable instrument because the only power it uses is the battery for the ohm-meter. Multimeters can be analog or digital type. Multimeters…
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Digital vs. Analog Instruments
Electronic instruments mainly voltmeters used either transistor or vacuum tubes. The later one is called The Vacuum Tube Voltmeter (VTVM) and the former one is called the Transistorized Voltmeter (TVM). In almost every field of electronics, VTVMs have been replaced by TVMs because of their numerous advantages. In TVM, due to the absence of a…
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Power Measurements in DC Circuits
Measurement of electric power is essential in both commercial industrial applications and domestic applications. Prior estimation and subsequent measurements of instantaneous and peak power demands of any installation are mandatory for design, operation and maintenance of the electric power supply network feeding it. How Power Measurements in DC circuits are done using an Ammeter and…