List of measuring instruments

An electricity meter measures energy directly in kilowatt-hours.

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.

• Length, distance, or range meter

For the ranges of length-values see: Orders of magnitude (length)

• Planimeter

For the ranges of area-values see: Orders of magnitude (area)

A measuring cup, a common instrument used to measure volume.

• Buoyant weight (solids)
• Eudiometer, pneumatic trough (gases)
• Flow measurement devices (liquids)
• Graduated cylinder (liquids)
• Measuring cup (grained solids, liquids)
• Overflow trough (solids)
• Pipette (liquids)

If the mass density of a solid is known, weighing allows to calculate the volume.

For the ranges of volume-values see: Orders of magnitude (volume)

• Circumferentor
• Cross staff
• Goniometer
• Graphometer
• Inclinometer
• Mural instrument
• Protractor
• Quadrant
• Reflecting instruments
  • Octant
  • Reflecting circles
  • Sextant
• Theodolite and total station

See also the section about navigation below.

• Level (instrument)
• Laser line level
• Spirit level

• Gyroscope

• Coordinate-measuring machine

• Gas meter
• Mass flow meter
• Metering pump
• Water meter

• Airspeed indicator
• LIDAR speed gun
• Radar speed gun, a Doppler radar device, using the Doppler effect for indirect measurement of velocity.
• Speedometer
• Tachometer (speed of rotation)
• Tachymeter
• Variometer (rate of climb or descent)
• Velocimetry (measurement of fluid velocity)

For the ranges of speed-values see: Orders of magnitude (speed)

• Accelerometer

A pair of scales: An instrument for measuring mass in a force field by balancing forces.

• 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

For the ranges of mass-values see: Orders of magnitude (mass)

• Ballistic pendulum

• Force gauge
• Spring scale
• Strain gauge
• Torsion balance
• Tribometer

Measuring absolute pressure in an accelerated reference frame: The principle of a mercury (Hg) barometer in the gravitational field of the earth.

• Anemometer (measures wind speed)
• Barometer used to measure the atmospheric pressure.
• Manometer (see Pressure measurement and Pressure sensor)
• Pitot tube (measures airspeed)
• Tire-pressure gauge in industry and mobility

For the ranges of pressure-values see: Orders of magnitude (pressure)

• Stroboscope
• Tachometer

For the value-ranges of angular velocity see: Orders of magnitude (angular velocity)

For the ranges of frequency see: Orders of magnitude (frequency)

• Dynamometer
• Prony brake
• Torque wrench

• Ballistic pendulum, indirectly by calculation and or gauging

• 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.

For the ranges of charge values see: Orders of magnitude (charge)

• Ammeter
• Clamp meter
• d'Arsonval galvanometer
• Galvanometer

• Oscilloscope allows quantifying time-dependent voltages
• Voltmeter

• Ohmmeter
• Time-domain reflectometer characterizes and locates faults in metallic cables by runtime measurements of electric signals.
• Wheatstone bridge

• Capacitance meter

• Inductance meter

• Electricity meter

• Wattmeter

• Field mill

See also the relevant section in the article about the magnetic field.

• Compass
• Hall effect sensor
• Magnetometer
• Proton magnetometer
• SQUID

For the ranges of magnetic field see: Orders of magnitude (magnetic field)

• 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.

A physical quantity introduced in chemistry; usually determined indirectly. If mass and substance type of the sample are known, then atomic- or molecular masses (taken from a periodic table, masses measured by mass spectrometry) give direct access to the value of the amount of substance. (See also Molar mass.) If specific molar values are given, then the amount of substance of a given sample may be determined by measuring volume, mass, or concentration. See also the subsection below about the measurement of the boiling point.

• Gas collecting tube gases

• Electromagnetic spectroscopy
• Galileo thermometer
• Gas thermometer principle: relation between temperature and volume or pressure of a gas (gas laws).
  • Constant pressure gas thermometer
  • Constant volume gas thermometer
• Liquid crystal thermometer
• Liquid thermometer principle: relation between temperature and volume of a liquid (coefficient of thermal expansion).
  • Alcohol thermometer
  • Mercury-in-glass thermometer
• Pyranometer principle: solar radiation flux density relates to surface temperature (Stefan–Boltzmann law)
• Pyrometers principle: temperature dependence of spectral intensity of light (Planck's law), 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 (instead of thermal conduction, or thermal convection) means: no physical contact becomes necessary in temperature measurement (pyrometry). Also note: thermal space resolution (images) found in thermography.
• Resistance thermometer principle: relation between temperature and electrical resistance of metals (platinum) (electrical resistance), range: 10 to 1,000 kelvins, application in physics and industry
• Solid thermometer principle: relation between temperature and length of a solid (coefficient of thermal expansion).
  • Bimetallic strip
• Thermistors principle: relation between temperature and electrical resistance of ceramics or polymers, range: from about 0.01 to 2,000 kelvins (−273.14 to 1,700 °C)
• Thermocouples principle: relation between temperature and voltage of metal junctions (Seebeck effect), range: from about −200 °C to +1350 °C
• Thermometer
• Thermopile is a set of connected thermocouples
• Triple point cell used for calibrating thermometers.

• Thermographic camera uses a microbolometer for detection of heat radiation.

See also Temperature measurement and Category:Thermometers. More technically related may be seen thermal analysis methods in materials science.

For the ranges of temperature-values see: Orders of magnitude (temperature)

An active calorimeter lacking a temperature measurement device.

This includes thermal mass or temperature coefficient of energy, reaction energy, heat flow, ... Calorimeters are called passive if gauged to measure emerging energy carried by entropy, for example from chemical reactions. Calorimeters are called active or heated if they heat the sample, or reformulated: if they are gauged to fill the sample with a defined amount of entropy.

• Actinometer heating power of radiation.
• Constant-temperature calorimeter, phase change calorimeter for example an ice calorimeter or any other calorimeter observing a phase change or using a gauged phase change for heat measurement.
• Constant-volume calorimeter, also called bomb calorimeter
• Constant-pressure calorimeter, enthalpy-meter, or coffee cup calorimeter
• Differential Scanning Calorimeter
• Reaction calorimeter

See also Calorimeter or Calorimetry

Entropy is accessible indirectly by measurement of energy and temperature.

Phase change calorimeter's energy value divided by absolute temperature give the entropy exchanged. Phase changes produce no entropy and therefore offer themselves as an entropy measurement concept. Thus entropy values occur indirectly by processing energy measurements at defined temperatures, without producing entropy.

• Constant-temperature calorimeter, phase change calorimeter
• Heat flux sensor uses thermopiles (which are connected thermocouples) to determine current density or flux of entropy.

The given sample is cooled down to (almost) absolute zero (for example by submerging the sample in liquid helium). At absolute zero temperature any sample is assumed to contain no entropy (see Third law of thermodynamics for further information). Then the following two active calorimeter types can be used to fill the sample with entropy until the desired temperature has been reached: (see also Thermodynamic databases for pure substances)

• Constant-pressure calorimeter, enthalpy-meter, active
• Constant-temperature calorimeter, phase change calorimeter, active

Processes transferring energy from a non-thermal carrier to heat as a carrier do produce entropy (Example: mechanical/electrical friction, established by Count Rumford). Either the produced entropy or heat are measured (calorimetry) or the transferred energy of the non-thermal carrier may be measured.

• calorimeter
• (any device for measuring the work which will or would eventually be converted to heat and the ambient temperature)

Entropy lowering its temperature—without losing energy—produces entropy (Example: Heat conduction in an isolated rod; "thermal friction").

• calorimeter

Concerning a given sample, a proportionality factor relating temperature change and energy carried by heat. If the sample is a gas, then this coefficient depends significantly on being measured at constant volume or at constant pressure. (The terminology preference in the heading indicates that the classical use of heat bars it from having substance-like properties.)

• Constant-volume calorimeter, bomb calorimeter
• Constant-pressure calorimeter, enthalpy-meter

The temperature coefficient of energy divided by a substance-like quantity (amount of substance, mass, volume) describing the sample. Usually calculated from measurements by a division or could be measured directly using a unit amount of that sample.

For the ranges of specific heat capacities see: Orders of magnitude (specific heat capacity)

• Dilatometer
• Strain gauge

• Differential Scanning Calorimeter gives melting point and enthalpy of fusion.
• Kofler bench
• Thiele tube

• Ebullioscope a device for measuring the boiling point of a liquid. This device is also part of a method that uses the effect of boiling point elevation for calculating the molecular mass of a solvent.

See also Thermal analysis, Heat.

This refers to particle density of fluids and compact(ed) solids like crystals, in contrast to bulk density of grainy or porous solids.

• Aerometer liquids
• Dasymeter gases
• Gas collecting tube gases
• Hydrometer liquids
• Pycnometer liquids
• Resonant frequency and damping analyser (RFDA) solids

For the ranges of density-values see: Orders of magnitude (density)

• Durometer

• Holographic interferometer
• Laser produced speckle pattern analysed.
• Resonant frequency and damping analyser (RFDA)
• Tribometer

• Strain gauge all below

• Resonant frequency and damping analyser (RFDA), using the impulse excitation technique: A small mechanical impulse causes the sample to vibrate. The vibration depends on elastic properties, density, geometry, and inner structures (lattice or fissures).

• Cam plastometer
• Plastometer

Measurement results (a) brittle (b) ductile with breaking point (c) ductile without breaking point.

• Universal testing machine

• Grindometer

• Rheometer
• Viscometer

• Polarimeter

• Tensiometer

• Tomograph, device and method for non-destructive analysis of multiple measurements done on a geometric object, for producing 2- or 3-dimensional images, representing the inner structure of that geometric object.
• Wind tunnel

This section and the following sections include instruments from the wide field of Category:Materials science, materials science.

• Capacitor

Such measurements also allow to access values of molecular dipoles.

• Gouy balance

For other methods see the section in the article about magnetic susceptibility.

See also Category:Electric and magnetic fields in matter

Phase conversions like changes of aggregate state, chemical reactions or nuclear reactions transmuting substances, from reactants into products, or diffusion through membranes have an overall energy balance. Especially at constant pressure and constant temperature, molar energy balances define the notion of a substance potential or chemical potential or molar Gibbs energy, which gives the energetic information about whether the process is possible or not - in a closed system.

Energy balances that include entropy consist of two parts: A balance that accounts for the changed entropy content of the substances, and another one that accounts for the energy freed or taken by that reaction itself, the Gibbs energy change. The sum of reaction energy and energy associated to the change of entropy content is also called enthalpy. Often the whole enthalpy is carried by entropy and thus measurable calorimetrically.

For standard conditions in chemical reactions either molar entropy content and molar Gibbs energy with respect to some chosen zero point are tabulated. Or molar entropy content and molar enthalpy with respect to some chosen zero are tabulated. (See Standard enthalpy change of formation and Standard molar entropy)

The substance potential of a redox reaction is usually determined electrochemically current-free using reversible cells.

• Redox electrode

Other values may be determined indirectly by calorimetry. Also by analyzing phase-diagrams.

• An X-ray tube, a sample scattering the X-rays and a photographic plate to detect them. This constellation forms the scattering instrument used by X-ray crystallography for investigating crystal structures of samples. Amorphous solids lack a distinct pattern and are identifiable thereby.

• Electron microscope
  • Scanning electron microscope
  • Transmission electron microscope
• Optical microscope uses reflectiveness or refractiveness of light to produce an image.
• Scanning acoustic microscope
• Scanning probe microscope
  • Atomic force microscope (AFM)
  • Scanning tunneling microscope (STM)
• Focus variation
• X-ray microscope

(See also Spectroscopy and List of materials analysis methods.)

Microphones in general, sometimes their sensitivity is increased by the reflection- and concentration principle realized in acoustic mirrors.

• Laser microphone
• Seismometer

• Microphone or hydrophone properly gauged
• Shock tube
• Sound level meter

A device for unmixing sun-light: the prism.

The electromagnetic spectrum

• Antenna (radio)
• Bolometer measuring the energy of incident electromagnetic radiation.
• Camera
• EMF meter
• Interferometer used in the wide field of interferometry
• Microwave power meter
• Optical power meter
• Photographic plate
• Photomultiplier
• Phototube
• Radio telescope
• Spectrometer
• T-ray detectors

(for lux meter, see the section about human senses and human body)

See also Category:Optical devices

• Polarizer

• Nichols radiometer

The measure of the total power of light emitted.

• Integrating sphere for measuring the total radiant flux of a light source

A Cathode-ray tube

• Crookes tube
• Cathode-ray tube, a phosphor-coated anode

• Stern–Gerlach experiment

Another visualization of the electromagnetic spectrum.

Ionizing radiation includes rays of "particles" as well as rays of "waves". Especially X-rays and gamma rays transfer enough energy in non-thermal, (single-) collision processes to separate electron(s) from an atom.

A cloud chamber detecting alpha-rays.

• Bubble chamber
• Cloud chamber
• Dosimeter, a technical device realizes different working principles.
• Geiger counter
• Ionisation chamber
• Microchannel plate detector
• Photographic plate
• Photostimulable phosphor plate
• Proportional counter
• Scintillation counter, Lucas cell
• Semiconductor detector

• Carbon dioxide sensor
• chromatographic device, gas chromatograph separates mixtures of substances. Different velocities of the substance types accomplish the separation.
• Colorimeter absorbance, and thus concentration
• Gas detector
• Gas detector in combination with mass spectrometer,
• mass spectrometer identifies the chemical composition of a sample on the basis of the mass-to-charge ratio of charged particles.
• Nephelometer or turbidimeter
• Oxygen sensor (= lambda sond)
• Refractometer, indirectly by determining the refractive index of a substance.
• Smoke detector
• Ultracentrifuge, separates mixtures of substances. In a force field of a centrifuge, substances of different densities separate.

• pH meter
• Saturated calomel electrode

• Hygrometer the density of water in air
• Lysimeter the balance of water in soil

Photometry is the measurement of light in terms of its perceived brightness to the human eye. Photometric quantities derive from analogous radiometric quantities by weighting the contribution of each wavelength by a luminosity function that models the eye's spectral sensitivity. For the ranges of possible values, see the orders of magnitude in: illuminance, luminance, and luminous flux.

• Photometers of various kinds:
  • Lux meter for measuring illuminance, i.e. incident luminous flux per unit area
  • Luminance meter for measuring luminance, i.e. luminous flux per unit area and unit solid angle
  • Light meter, an instrument used to set photographic exposures. It can be either a lux meter (incident-light meter) or a luminance meter (reflected-light meter), and is calibrated in photographic units.
• Integrating sphere for collecting the total luminous flux of a light source, which can then be measured by a photometer
• Densitometer for measuring the degree to which a photographic material reflects or transmits light

• Tristimulus colorimeter for quantifying colors and calibrating an imaging workflow

Synthetic Aperture Radar (SAR) instruments measure radar brightness, Radar Cross Section (RCS), which is a function of the reflectivity and moisture of imaged objects at wavelengths which are too long to be perceived by the human eye. Black pixels mean no reflectivity (e.g. water surfaces), white pixels mean high reflectivity (e.g. urban areas). Colored pixels can be obtained by combining three gray-scaled images which usually interpret the polarization of electromagnetic waves. The combination R-G-B = HH-HV-VV combines radar images of waves sent and received horizontally (HH), sent horizontally and received vertically (HV) and sent and received vertically (VV). The calibration of such instruments is done by imaging objects (calibration targets) whose radar brightness is known.

• Headphone, loudspeaker, sound pressure gauge, for measuring an equal-loudness contour of a human ear.
• Sound level meter calibrated to an equal-loudness contour of the human auditory system behind the human ear.

• Olfactometer, see also Olfaction.

• Medical thermometer, see also infrared thermometer

Blood-related parameters are listed in a blood test.

• Electrocardiograph records the electrical activity of the heart
• Glucose meter for obtaining the status of blood sugar.
• Sphygmomanometer, a blood pressure meter used to determine blood pressure in medicine. See also Category:Blood tests

A spirometer, inhaling into pipe a fills volume b, the rest balances forces.

• Spirometer

• Capnograph

• Electroencephalograph records the electrical activity of the brain

• Ergometer

• Body fat meter

An echocardiogram processed into a three dimensional representation.

• Computed tomography
• Magnetic resonance imaging
• Medical ultrasonography
• Radiology
• Tomograph, device and method for non-destructive analysis of multiple measurements done on a geometric object, for producing 2- or 3-dimensional images, representing the inner structure of that geometric object.

See also: Category:Physiological instruments and Category:Medical testing equipment.