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The first moving-pointer current-detecting device was the galvanometer in 1820. These were used to measure resistance and voltage by using a Wheatstone bridge, and comparing the unknown quantity to a reference voltage or resistance. While useful in the lab, the devices were very slow and impractical in the field.
Demonstration model of a moving iron ammeter. As the current through the coil increases, the plunger is drawn further into the coil and the pointer deflects to the right. An ammeter (abbreviation of ampere meter) is an instrument used to measure the current in a circuit. Electric currents are measured in amperes (A), hence the name. For direct ...
a spoon used to measure an amount of an ingredient, either liquid or dry megger: electrical insulation mercury barometer: Atmospheric pressure micrometer: small distances multimeter: electrical potential, resistance, and current nephoscope: to measure the speed and direction of clouds nephelometer: particle in a liquid odometer: distance ...
Measures current Capacitance meter: Measures the capacitance component Current clamp: Measures current without physical connection Curve tracer: Applies swept signals to a device and allows display of the response Cos Phi Meter: Measures the power factor Distortionmeter: Measures the distortion added to a circuit Electricity meter
In a device called an oscillograph, the moving beam of light is used, to produce graphs of current versus time, by recording measurements on photographic film. The string galvanometer is a type of mirror galvanometer so sensitive that it was used to make the first electrocardiogram of the electrical activity of the human heart.
An ohmmeter is an electrical instrument that measures electrical resistance (the opposition offered by a circuit or component to the flow of electric current). Multimeters also function as ohmmeters when in resistance-measuring mode. An ohmmeter applies current to the circuit or component whose resistance is to be measured.
Instruments permanently mounted in a panel are used to monitor generators or other fixed apparatus. Portable instruments, usually equipped to also measure current and resistance in the form of a multimeter are standard test instruments used in electrical and electronics work. Any measurement that can be converted to a voltage can be displayed ...
Solid-state electrometers are often multipurpose devices that can measure voltage, charge, resistance and current. They measure voltage by means of "voltage balancing", in which the input voltage is compared with an internal reference voltage source using an electronic circuit with a very high input impedance (of the order of 10 14 Ω).