Tag: Instruments
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China First Eco-Friendly High-Temperature Melt Pressure Transducer Without Mercury Filling
Ziasiot Sensor pioneered China’s first mercury-free, eco-friendly high-temperature melt pressure transducer, which marking a significant technological breakthrough in the melt pressure industry. A Safer Alternative for extrusion melt pressure applications Traditional melt pressure transducers and thermometers have long relied on mercury (Hg) as a filling medium. However, mercury poses severe health and environmental risks due to its toxic…
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Distortion Meter: Function, Components & Controls
The Function of a Distortion Meter A distortion meter is used to measure the total harmonic distortion content in an input waveform. The rms level of the distortion is usually measured as a percentage of the rms level of the complete waveform. Alternatively, a decibel measurement may be employed. A sine wave input to an…
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How to Calibrate a DC Ammeter using a Potentiometer
We can calibrate a dc ammeter by connecting it in series with a precision resistor/standard resistor, and accurately measuring the resistor voltage drop. The level of ammeter current is determined by dividing the resistor voltage drop by its resistance value. When the resistor value is known precisely, and the voltage drop is measured by a…
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Absolute vs. Secondary Instruments
Measuring instruments may be classified as either absolute instruments or secondary instruments. Absolute Instruments This type of instruments gives the value of the measurand in terms of instrument constant and its deflection; this instrument type doesn’t require comparison with any other standard. For instance, the tangent galvanometer gives the value of the current to be…
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How to Measure Pressure using a U-tube Manometer
There are three categories of pressure measurement, namely absolute pressure, gauge pressure and differential pressure. The absolute pressure is the differences between the pressure at a particular point in a fluid and the absolute zero of pressure, that is, a complete vacuum. When the pressure measuring device measures the difference between the unknown pressure and…
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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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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…