Voltmeter

Digital voltmetervolt metervoltmetersAC voltmeterDC voltmeterdigitaldigital volt meterDigital voltmetersmetervacuum tube volt meters (VTVMs)
A voltmeter is an instrument used for measuring electrical potential difference between two points in an electric circuit.wikipedia
142 Related Articles

Multimeter

digital multimeterdigital multimetersmultitester
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. Today these circuits use a solid-state amplifier using field-effect transistors, hence FET-VM, and appear in handheld digital multimeters as well as in bench and laboratory instruments.
Vacuum tube voltmeters or valve voltmeters (VTVM, VVM) were used for voltage measurements in electronic circuits where high input impedance was necessary.

Electrostatic voltmeter

electrostatic principle
Voltmeters operating on the electrostatic principle use the mutual repulsion between two charged plates to deflect a pointer attached to a spring.
Electrostatic voltmeter can refer to an electrostatic charge meter, known also as surface DC voltmeter, or to a voltmeter to measure large electrical potentials, traditionally called electrostatic voltmeter.

Electric potential

electrical potentialelectrostatic potentialpotential
A voltmeter is an instrument used for measuring electrical potential difference between two points in an electric circuit.
Inside metals (and other solids and liquids), the energy of an electron is affected not only by the electric potential, but also by the specific atomic environment that it is in. When a voltmeter is connected between two different types of metal, it measures not the electric potential difference, but instead the potential difference corrected for the different atomic environments.

Weston cell

standard cellstandard cellsWeston
In laboratories, the Weston Cell is used as a standard voltage for precision work. Less expensive DVMs often have input resistance on the order of 10 MΩ. Precision DVMs can have input resistances of 1 GΩ or higher for the lower voltage ranges (e.g. less than 20 V). To ensure that a DVM's accuracy is within the manufacturer's specified tolerances, it must be periodically calibrated against a voltage standard such as the Weston cell.
The Weston cell is a wet-chemical cell that produces a highly stable voltage suitable as a laboratory standard for calibration of voltmeters.

Kaypro

Kaypro II
The first digital voltmeter was invented and produced by Andrew Kay of Non-Linear Systems (and later founder of Kaypro) in 1954.
Kaypro began as Non-Linear Systems, a maker of electronic test equipment, founded in 1952 by Andrew Kay, the inventor of the digital voltmeter.

Analog-to-digital converter

ADCanalog to digital converteranalog-to-digital conversion
Analog voltmeters move a pointer across a scale in proportion to the voltage of the circuit; digital voltmeters give a numerical display of voltage by use of an analog to digital converter. DVMs are usually designed around a special type of analog-to-digital converter called an integrating converter.
Converters of this type (or variations on the concept) are used in most digital voltmeters for their linearity and flexibility.

Electronic test equipment

test equipmentelectronic test instrumenttest
Electronic test equipment
Voltmeter (Measures voltage)

Ammeter

microammetermoving coil meterampere-meter
Ammeter
This type of meter movement is extremely common for both ammeters and other meters derived from them, such as voltmeters and ohmmeters.

Solenoid voltmeter

Solenoid voltmeter
A solenoid voltmeter is a specific type of voltmeter electricians use to test electrical power circuits.

Andrew Kay

The first digital voltmeter was invented and produced by Andrew Kay of Non-Linear Systems (and later founder of Kaypro) in 1954.
At NLS he invented the digital voltmeter, in 1954.

Electrometer

capillary electrometerelectrographelectrometers
Electrometer
A modern electrometer is a highly sensitive electronic voltmeter whose input impedance is so high that the current flowing into it can be considered, for most practical purposes, to be zero.

Integrating ADC

dual-slope analog to digital converterdual slope ADCsdual-slope
DVMs are usually designed around a special type of analog-to-digital converter called an integrating converter.
Voltmeter

Potentiometer (measuring instrument)

potentiometrypotentiometerno current
Potentiometer (measuring instrument)
When measuring an unknown voltage and the galvanometer reads zero, no current is drawn from the unknown voltage and so the reading is independent of the source's internal resistance, as if by a voltmeter of infinite resistance.

Class of accuracy in electrical measurements

Class of accuracy in electrical measurements
In electrical engineering characteristics like current or voltage can be measured by an ammeter, a voltmeter, a multimeter, etc. The ammeter is used in series with the load, so the same current flows through the load and the ammeter.

Voltage divider

voltage divisionloading effectpotential divider
Voltage divider
A voltage divider can be used to scale down a very high voltage so that it can be measured by a volt meter.

Amplifier

amplifiersamplificationamplified
Meters using amplifiers can measure tiny voltages of microvolts or less.

Jacques-Arsène d'Arsonval

d'ArsonvalJacques A. d'ArsonvalJacques Arsene d'Arsonval
[[Image:Galvanometer diagram.svg|thumb|A moving coil galvanometer of the d'Arsonval type.

Galvanometer

tangent galvanometernull detectorgalvanoscope
A moving coil galvanometer can be used as a voltmeter by inserting a resistor in series with the instrument.

Resistor

Resistor controlresistorsResistance
A moving coil galvanometer can be used as a voltmeter by inserting a resistor in series with the instrument.

Series and parallel circuits

seriesparallelin series
A moving coil galvanometer can be used as a voltmeter by inserting a resistor in series with the instrument.

Rectifier

rectificationrectifiedrectifiers
Measurement of AC voltage requires a rectifier in the circuit so that the coil deflects in only one direction.

Field-effect transistor

field effect transistorFETgate
Today these circuits use a solid-state amplifier using field-effect transistors, hence FET-VM, and appear in handheld digital multimeters as well as in bench and laboratory instruments.

Voltage reference

voltage standardbandgap referencesreference voltage
Less expensive DVMs often have input resistance on the order of 10 MΩ. Precision DVMs can have input resistances of 1 GΩ or higher for the lower voltage ranges (e.g. less than 20 V). To ensure that a DVM's accuracy is within the manufacturer's specified tolerances, it must be periodically calibrated against a voltage standard such as the Weston cell.