Photoelectric Transducer

Definition: The photoelectric transducer converts the light energy into electrical energy. It is made of semiconductor material. The photoelectric transducer uses a photosensitive element, which ejects the electrons when the beam of light absorbs through it. The discharges of electrons vary the property of the photosensitive element. Hence the current induces in the devices. The…

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Difference Between Wattmeter & Energy Meter

The significant difference between the Wattmeter and the energy meter is that the Wattmeter measures the electrical power flows in the circuit, whereas the energy meter measures the total electrical energy consumes by the electrical load. The other differences between Wattmeter and Energy Meter are represented below in the comparison chart. Before knowing the differences…

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Hygrometer

Definition: Hygrometer uses for measuring the humidity present in the surrounding environment. The term humidity means the amount of water vapour present in the gas. The physical properties of the material changes by the effect of the humidity and this principle use in hygrometer for measurement. The humidity is classified into two types. Absolute Humidity…

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Schering Bridge

The Schering bridge use for measuring the capacitance of the capacitor, dissipation factor, properties of an insulator, capacitor bushing, insulating oil and other insulating materials. It is one of the most commonly used AC bridge. The Schering bridge works on the principle of balancing the load on its arm. Let, C1 – capacitor whose capacitance…

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Kelvin Bridge

Definition: The Kelvin bridge or Thompson bridge is used for measuring the unknown resistances having a value less than 1Ω. It is the modified form of the Wheatstone Bridge. What is the need of Kelvin Bridge? Wheatstone bridge use for measuring the resistance from a few ohms to several kilo-ohms. But error occurs in the…

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Difference between Thermocouple & Thermistor

The most significant difference between the thermocouple and the thermistor is that in thermocouple the sensing parameter is the voltage that induces between the two dissimilar metals. Whereas in thermistor the resistance is the temperature sensing parameter. The other differences between the thermistor and the thermocouple are shown below in the comparison chart. The thermocouple…

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Three Phase Wattmeter

Definition: Three-Phase Wattmeter is used for measuring the power of the three-phase circuit. In three-phase Wattmeter, the two separate Wattmeter are mounted together in the single unit. Their moving coils are placed on the same spindle. Three-Phase Wattmeter has two elements. The single element is the combination of the pressure coil and the current coil. The…

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Volt-Ohm-Milli-Ammeter (VOM)

Definition: The multimeter or volt-ohm-milli-ammeter (VOM) is the type of meter which performs the multiple functions. In other words, in VOM the multiple measuring functions are combined in a single unit. The multimeter is used for measuring voltage, current and resistance. It contains the circuitry switch which makes the meter to operate like a voltmeter,…

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Torque/Weight Ratio of an Indicating Instrument

Definition: The ratio of torque to the weight of the moving part of an instrument is known as a torque/weight ratio. It indexes the performance of the instrument. The higher value of torque/weight ratio shows that the instrument has good performances. The value of torque/weight ratio of the moving part of the instrument should not be…

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Phase Sequence Indicator

Definition: The instrument uses for determining the sequence of the three-phase system is known as the phase sequence indicator. The change in the sequence of the power supply changes the direction of rotation of the machine. Because of which the entire supply system will be affected. For proper connection, it is essential to know the…

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