Tag: Instruments
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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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Electric Wiring Testing & Inspection Instruments Requirements
In order to carry out the verification process proficiently, the person conducting the inspection and test must be in possession of suitable test instruments. In this article, we look at some of the key requirements for electric wiring testing and inspection instruments. The commonly used instruments for electric wiring testing and inspection include: Nowadays we…
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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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Instrument Grounding: General Guidelines
Specific attention must be paid to instrument grounding, especially where field instruments are connected to a computer or microprocessor based control system. Where cable screens are used, ground continuity of screens must be maintained throughout the installation with the grounding at one point only such as that in the control room. At the field end…
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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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What are Virtual Instruments?
Virtual instruments (VI) are instruments based on computer software whose controls and displays are presented on a computer screen and whose operation and settings are controlled by the keyboard and mouse. Instead of purchasing a number of expensive, dedicated, standalone instruments, users find it less costly to purchase a computer with a multichannel, analog-to-digital converter…
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What is Calibration of the Sensor?
Calibration of the sensor is the relationship between the physical measurement variable input and the signal variable output for that specific sensor. Typically, a sensor or an entire instrument system is calibrated by providing a known physical input to the system and recording the output. The data is plotted on a calibration curve such as…