AC Voltmeter using Rectifiers: AC Voltmeter using Rectifiers - Rectifier type instruments generally use a PMMC movement along with a rectifier arrangement. Silicon diodes are preferred because of their low reverse current and high forward…
DC Standard Differential Voltmeter: A basic DC Standard Differential Voltmeter can be operated in different modes. The three basic modes of operation are as a dc voltage standard, as a dc differential voltmeter, and as…
Differential Voltmeter: The Differential Voltmeter technique, is one of the most common and accurate methods of measuring unknown voltages. In this technique, the voltmeter is used to indicate the difference between known and unknown voltages,…
Solid State Voltmeter: Solid State Voltmeter - Figure 4.13 shows the circuit of an electronic voltmeter using an IC OpAmp 741C. This is a directly coupled very high gain amplifier. The gain of the OpAmp…
Chopper type DC Amplifier Voltmeter (Microvoltmeter): Chopper type DC Amplifier Voltmeter the dc input voltage is converted into an ac voltage, amplified by an ac amplifier and then converted back into a dc voltage proportional…
Transistor Voltmeter (TVM): Transistor Voltmeter - Direct coupled amplifiers are economical and hence used widely in general purpose low priced VTVM' s. Figure 4.9 gives a simplified schematic diagram of a dc coupled amplifier with…
DC Meter: The most commonly used dc meter is based on the fundamental principle of the motor. The motor action is produced by the flow of a small amount of current through a moving coil…
Measurements of very Large Currents by Thermocouples: Measurements of very Large Currents by Thermocouples - Thermocouples instruments with heaters large enough to carry very large currents may have an excessive skin effect. Ordinary shunts cannot…
Various Factors of Frequency Effect on Calibration: The Various Factors of Frequency Effect on Calibration such as: Skin effect Non uniform distribution of current along the heater wires Spurious capacitive currents 1. Skin Effect: The…
Thermocouple Principle and Types of Thermocouple: Thermocouple Principle consists of a junction of two dissimilar wires, so chosen that a voltage is generated by heating the junction. The output of a thermocouple is delivered to…
