List of measuring instruments
A measuring instrument is a device to measure a physical quantity. In the physical sciences, quality assurance, and engineering, measurement is the activity of obtaining and comparing physical quantities of real-world objects and events. Established standard objects and events are used as units, and the process of measurement gives a number relating the item under study and the referenced unit of measurement. Measuring instruments, and formal test methods which define the instrument's use, are the means by which these relations of numbers are obtained. All measuring instruments are subject to varying degrees of instrument error and measurement uncertainty.
These instruments may range from simple objects such as rulers and stopwatches to electron microscopes and particle accelerators. Virtual instrumentation is widely used in the development of modern measuring instruments.
Time
In the past, a common time measuring instrument was the sundial. Today, the usual measuring instruments for time are clocks and watches. For highly accurate measurement of time an atomic clock is used.Stopwatches are also used to measure time in some sports.
Energy
Energy is measured by an energy meter. Examples of energy meters include:Electricity meter
An electricity meter measures energy directly in kilowatt-hours.Gas meter
A gas meter measures energy indirectly by recording the volume of gas used. This figure can then be converted to a measure of energy by multiplying it by the calorific value of the gas.Power (flux of energy)
A physical system that exchanges energy may be described by the amount of energy exchanged per time-interval, also called power or flux of energy.*
For the ranges of power-values see: Orders of magnitude.
Action
Action describes energy summed up over the time a process lasts. Its dimension is the same as that of an angular momentum.- A phototube provides a voltage measurement which permits the calculation of the quantized action of light.
Geometry
Dimensions (size)
Length (distance)
- Length, distance, or range meter
Area
- Planimeter
Volume
- Buoyant weight
- Eudiometer, pneumatic trough
- Flow measurement devices
- Graduated cylinder
- Measuring cup
- Overflow trough
- Pipette
For the ranges of volume-values see: Orders of magnitude
Angle
- Circumferentor
- Cross staff
- Goniometer
- Graphometer
- Inclinometer
- Mural instrument
- Protractor
- Quadrant
- Reflecting instruments
- *Octant
- *Reflecting circles
- *Sextant
- Theodolite and total station
Orientation in three-dimensional space
Level
- Level
- Laser line level
- Spirit level
Direction
- Gyroscope
Coordinates
- Coordinate-measuring machine
Mechanics
Mass or volume flow measurement
- Gas meter
- Mass flow meter
- Metering pump
- Water meter
Speed or velocity (flux of length)
- Airspeed indicator
- LIDAR speed gun
- Radar speed gun, a Doppler radar device, using the Doppler effect for indirect measurement of velocity.
- Speedometer
- Tachometer
- Tachymeter
- Variometer
- Velocimetry
Acceleration
- Accelerometer
Mass
- Balance
- Check weigher measures precise weight of items in a conveyor line, rejecting underweight or overweight objects.
- Inertial balance
- Katharometer
- Mass spectrometers measure the mass-to-charge ratio, not the mass, of ionised particles.
- Weighing scale
Linear momentum
- Ballistic pendulum
Force (flux of linear momentum)
- Force gauge
- Spring scale
- Strain gauge
- Torsion balance
- Tribometer
Pressure (flux density of linear momentum)
- Anemometer
- Barometer used to measure the atmospheric pressure.
- Manometer
- Pitot tube
- Tire-pressure gauge in industry and mobility
Angular velocity or rotations per time unit
- Stroboscope
- Tachometer
For the ranges of frequency see: Orders of magnitude
Torque
- Dynamometer
- Prony brake
- Torque wrench
Energy carried by mechanical quantities, mechanical work
- Ballistic pendulum, indirectly by calculation and or gauging
Electricity, electronics, and electrical engineering
Electrical charges interact via a field. That field is called electric field.If the charge doesn't move. If the charge moves, thus realizing an electric current, especially in an electrically neutral conductor, that field is called magnetic.
Electricity can be given a quality — a potential. And electricity has a substance-like property, the electric charge.
Energy in elementary electrodynamics is calculated by multiplying the potential by the amount of charge found at that potential: potential times charge.
Electric charge
- Electrometer is often used to reconfirm the phenomenon of contact electricity leading to triboelectric sequences.
- Torsion balance used by Coulomb to establish a relation between charges and force, see [|above].
Electric current (current of charge)
- Ammeter
- Clamp meter
- d'Arsonval galvanometer
- Galvanometer
Voltage (electric potential difference)
- Oscilloscope allows quantifying time-dependent voltages
- Voltmeter
Electric resistance, conductance, and conductivity
- Ohmmeter
- Time-domain reflectometer characterizes and locates faults in metallic cables by runtime measurements of electric signals.
- Wheatstone bridge
Electric capacitance
- Capacitance meter
Electric inductance
- Inductance meter
Energy carried by electricity or electric energy
- Electricity meter
Power carried by electricity (current of energy)
- Wattmeter
Electric field (negative gradient of electric potential, voltage per length)
- Field mill
Magnetic field
- Compass
- Hall effect sensor
- Magnetometer
- Proton magnetometer
- SQUID
Combination instruments
- Multimeter, combines the functions of ammeter, voltmeter, and ohmmeter as a minimum.
- LCR meter, combines the functions of ohmmeter, capacitance meter, and inductance meter. Also called component bridge due to the bridge circuit method of measurement.
Thermodynamics
And a substance-like property, — the entropy; for example: One glowing coal won't heat a pot of water, but a hundred will.
Energy in thermodynamics is calculated by multiplying the thermal potential by the amount of entropy found at that potential: temperature times entropy.
Entropy can be created by friction but not annihilated.
Amount of substance
- Gas collecting tube gases
Temperature
- Electromagnetic spectroscopy
- Galileo thermometer
- Gas thermometer principle: relation between temperature and volume or pressure of a gas.
- *Constant pressure gas thermometer
- *Constant volume gas thermometer
- Liquid crystal thermometer
- Liquid thermometer principle: relation between temperature and volume of a liquid.
- *Alcohol thermometer
- *Mercury-in-glass thermometer
- Pyranometer principle: solar radiation flux density relates to surface temperature
- Pyrometers principle: temperature dependence of spectral intensity of light, i.e. the color of the light relates to the temperature of its source, range: from about −50 °C to +4000 °C, note: measurement of thermal radiation means: no physical contact becomes necessary in temperature measurement. Also note: thermal space resolution found in thermography.
- Resistance thermometer principle: relation between temperature and electrical resistance of metals , range: 10 to 1,000 kelvins, application in physics and industry
- Solid thermometer principle: relation between temperature and length of a solid.
- *Bimetallic strip
- Thermistors principle: relation between temperature and electrical resistance of ceramics or polymers, range: from about 0.01 to 2,000 kelvins
- Thermocouples principle: relation between temperature and voltage of metal junctions, range: from about −200 °C to +1350 °C
- Thermometer
- Thermopile is a set of connected thermocouples
- Triple point cell used for calibrating thermometers.
Imaging technology
- Thermographic camera uses a microbolometer for detection of heat radiation.
For the ranges of temperature-values see: Orders of magnitude