Measuring instrument

Measuring instruments used to determine physical quantities. Mostly they run as part of a measurement by means of a scale or digital display at a quantitative assessment of the quantity to be measured, at registration apparatus the data is printed directly on paper or another durable ( storage ) medium. This statement, the measured value is given as the product of a numerical value and unit. The measuring principle underlying methods are specified in metrology. General characteristics of the measuring instruments according to DIN 1319-1 are listed under measuring equipment.

Instruments for making measurements generally include the group of measuring equipment. If these are used for testing, they are named according to DIN 1319-2 as test equipment.

The measurement device may malfunction or the measured value can contain measurement deviations; these are generally attributed respectively to estimate their size. Particularly accurate measuring instruments can be used for calibration, adjustment or calibration of other instruments (see also Monitoring of measuring equipment ). For calculated values, a measurement uncertainty can be specified.

• 2.1 Special equipment for size
• 2.2 magnetic field
• 2.3 Measurement of radioactivity and radiation 2.3.1 More

• 3.1 speed 3.1.1 speed
• 3.1.2 acceleration
• 3.1.3 Distance covered
• 3.1.4 performance

• 3.8.1 Quality of measurements

• 5.1 Measurement of material properties 5.1.1 Hardness test

• 5.2.1 Data and Communication Technology 5.2.1.1 Local buses
• 5.2.1.2 fieldbuses
• 5.2.1.3 Ethernet

• 7.1 Technical device for measurements in medicine

Measurement of non- electrical quantities

Basic Measuring Instruments

Without the basic measuring devices to determine the time and for the measurement of lengths and the simple counting no other instruments can be made ​​or used. Other sizes also basic variables are derived or the gauges are determined by application of these sizes.

Timekeeping

The time is measured with different clocks:

• Sundials are historical, use only in specific areas ( teaching purposes, decoration)
• Hourglasses are historical, application only in individual areas
• Water clocks are historical ( for measuring time - not flow! )
• Flower watches are very inaccurate devices for measuring time, but very pretty to look at. Use as show pieces for teaching purposes.
• Fire watches were cultic timepieces that burned an aromatic compound.
• Candles watches are historical, application only in individual areas
• Time lamps are historically, oil lamps with scaled glass container
• Radio controlled clock receives the exact time signal an atomic clock via radio signal.
• Pendulum clock measures the time over the period of oscillation of a pendulum.
• Passages instrument measures the transit time of stars (combined with chronograph ).
• Chronometer measures time (mechanical or quartz oscillators short )
• Chronograph measures the time (mechanical or quartz ) and records or prints the time relating to (often with a different size together, eg star passes).
• Stopwatch mechanical or electrical / electronic
• Timer mechanically or electrically with audible, visual alarm or / and switching options
• Quartz watch measures time with a controlled by quartz crystal oscillator.
• Interval meter measures frequencies and time intervals on the basis of an oscillator.
• Atomic clock measures the time due to the high stability of atomic vibrations. With hydrogen measles the most accurate currently available watches.

Length measurement

In principle, we distinguish two types of simple measuring means for measuring the length: the Line measure which represents the measurement by the distance between two bars and the final size ( for example the standard meter ), which is done by the distance between two surfaces.

• Gauge, analog and digital displaying up to 0.001 mm
• Calipers ( colloquially " sliding " or " sliding caliper " ), accurate to 0.05 mm
• The Knopfmaß, little easier calipers, example of the development of length measurement: historically an important step today only with low accuracy requirements, as no vernier
• Thread counter measures line widths and line spacing when printing.
• Caliper, forestry for the determination of stem diameters
• Ruler, metal ruler, measuring ruler; Accuracy up to 0.3 mm
• Meter rule, folding rule ( colloquially " ruler "); Accuracy up to 1.0 mm
• Measuring wheel for rapid shutdown of a measurement path (accuracy depending on the structure to 1 ‰)
• Tape measure for measurements up to 50 m, maximum 100 m (accuracy 1-3 cm) see also odometer and cyclometer (metrology)

Displacement sensors such as:

• Laser rangefinder, laser interferometer
• Ultrasonic rangefinder
• Cable length sensor (accuracy possible depending on the structure to 0.01 mm)
• Glass scale
• Capacitive sensor
• Laser surface velocimeter used for length measurement on continuously produced goods and strip products.

Count

Counting is the most basic measurement principle: Even at the time or length measurement is often simply counted. With the penetration of the metrology by digital methods to the measurement principle has become of paramount importance.

Counting in the metrological sense, determining the number (see also piece set). Counters measure the number of objects or events, when temporary census they determine their frequency:

• Hand counter for individual events, decimal with carries several pockets rolls or digits wheels
• Revolution counter with additional mechanical or optical detection of a tic mark
• Wheels works in many mechanical measuring instruments for evaluating the number of turns for other metrics, such as the integrating ( summing up ) working energy meters, water meters, odometers. The earliest computing machines were pure Scorers
• Geiger counter for the determination of radioactive decay events
• Electronic meter see the section counter in the article Digital Sensor Technology
• Counting for the replacement of the activity of counting by weighing at the same time present the same objects with known piece weight

Other gauges elementary sizes

Surface area measurement

Meters the area of ​​measurement ( Planimetrierung )

• Planimeter, a mechanical apparatus for determination of flat surfaces in maps or drawings
• Pantograph, a scale converter, which can be used by way of transfer to a screening of the surface measurement.

Volume measurement

The determination of both the void volume and the volume of solids, liquids or gases is realized historically by the hollow body or scaled measuring vessels, but mostly through volume calculation.

• Graduated cylinder to measure based on the displacement of glass or plastic or other, with or without Scale
• Volumeters, for the body, which should not come into contact with liquid
• Capillary by means of the following weighting or reading a scale ( for example when indirectly thermometer for determining the temperature from the change in volume )
• Bushel, an example of a historical volume - level overview in ( history of weights and measures )
• Pipette to meter quantities of a vessel to another
• Measuring cups, teaspoons and tablespoons, as measures in the kitchen
• Measurement lift to remove an existing instrument usually made of glass around a lot of liquid from a vessel ( sampling)
• Kubizierapparat (measuring bell ), for the determination of gases and liquids,
• Flowmeter dynamic volume measurement see below

Location determination, angle and direction measurement

Geodesy: All devices for angle measurement in the field are also suitable (good different) for location determination. For this purpose, maps or coordinates are needed. By measuring angles and beams set height or height difference of objects can be calculated.

• Protractor as a tool (see also protractor )
• Bevel, mainly for transferring angles onto workpieces
• Messlot for determining the vertical
• Chorobates leveling ( historical, example: construction of aqueducts )
• Groma for bearings ( historically ). In a bar, a coordinate system is attached at each end of the axles a Messlot. After alignment of the instrument bearings are available
• Dioptra for bearings ( historical )
• Measure 3D coordinate measuring machine, by means of probing, optics. Manual as CNC
• Compass to determine magnetic north (navigation)
• Gyrocompass for the determination of true north (or south) (ship navigation )
• Laser gyroscope measures wear-free rotation.
• Jacob's staff historical, celestial navigation and to determine the height of an object
• Gnomon, gnomon, historically, to determine the latitude of a place
• Astrolabe historical, celestial navigation. As Ni2 - astrolabe for modern astrometry
• Sextant used for angle measurement between two landmarks. Terrestrial and astro - navigation.
• Heliotrope historically a solar mirror for survey points
• Heliometer to the 19th century, precise diameter and angle measurement in astronomy
• Spirit level for horizontal and / or vertical alignment
• Plummet, historical precursor of the water balance ( application where, on reading level)
• Tube level - physical leveling ( principle of communicating vessels)
• Leveling to the geometric height measurement
• Theodolite to measure angles and geometric relations in space
• Total station for angle and distance measurement
• Planimeter to measure areas (on drawings, plans, etc.)
• Measuring cameras - precision cameras for photogrammetry
• Fringe projection sensors - for non-contact shape measurement
• GPS satellite navigation, direct display of the 3D position
• Zenith zenith telescope and camera: for the measurement of Sternörtern and plumb
• Radio telescope to measure astronomical radio sources ( quasars and VLBI ).

Mass, weight, density, etc.

The weight measurement is a field of mass metrology. While earlier scales were determined mainly by the clever design of the mechanical elements such as levers, weights and / or springs, the weighing of today is characterized by the electronics.

• Scales are used to determine the mass of bodies
• Compare beam balances the mass of a sample with calibrated weights
• Orientation Scale ( historical postal scales )
• Spring scales determine the mass of a specimen from its weight
• Pycnometer to measure the specific gravity or density
• Refractometers measure the refractive index, especially of liquids, and also in turn sizes as must weight, salinity, generally concentrations
• Laktodensimeter measure the density of milk.
• Turbidity Meters determine the proportion of solids in liquids
• Gas collection pipes or Dasymeter allow mass and volume of a gas sample to be determined.

Temperature

Thermometry is the science of temperature measurement - measurement by thermometer in different versions.

Early thermometers

• Melts boiling water, or wax: assessment by alchemists
• Galileo Thermometer: Gravity / Density (named after Galileo Galilei)
• Dilatometric thermometers (liquid or metal rod, direct reading on scale): Room and outdoor thermometer, sling thermometer, stem thermometer
• Bimetallic thermometers: use of the different expansion coefficients of two metals
• Thermochromatic color: color change at a certain temperature
• Seger cones: moldings which change their firmness and contour at a specific temperature. Melting point can also be used in the opposite direction

Modern thermometers

• Resistance thermometer ( resistance change, eg with Pt100 sensor or a silicon transistor)
• Thermocouples ( see also: thermoelectricity )
• Radiation thermometer (pyrometer )
• Bolometers measure the effect of (heat) radiation on a specimen
• Raman thermometer based on the Raman spectroscopy
• Thermography: non-contact surface temperature measurement with infrared radiation. " Thermal imaging " in chiaroscuro presentation or in color (see picture)

Measuring electromagnetic quantities

A basic distinction in measuring electromagnetic quantities between analog and digital measuring instrument or measuring factory. When analog meter is to be expected with a parallax error.

• The description of the electromagnetic units can be found in the list of physical quantities.

Special unit for one size

• Voltmeters, colloquially voltmeter, measure the voltage or potential difference between two points.
• The rotary voltmeter, colloquially electroscopes, measure the electric field ( potential difference ) between two points energized.
• Ammeters, colloquially ammeter, electricity or charge compensating measure between two points. See also: current probe ( Special design) Galvanometer are special instruments for measuring very small DC currents.

• The Wheatstone bridge ohmic resistances determined by a comparison method as well as small changes in resistance by a rash method.
• The AC voltage bridge determines AC voltage resistors.

Magnetic field

• The compass points to the magnetic poles of the earth, if he is not distracted.
• Hall probes measure magnetic field or current.
• Proton magnetometer only measure the absolute magnetic field strength.
• Ranger probes are used to determine the vector magnetic field.
• Fluxmeter measure the magnetic flux. Use often in combination with a Helmholtz coil.
• Leakage current measuring instruments measure very small currents flowing through the protective conductor or shielding.
• SQUID Superconducting Quantum Interference Device. For the measurement of very small magnetic fields. Use in magnetoencephalography (MEG ). This is a measurement of the magnetic activity of the brain.
• Tesla meter, also called Gauss meter, measure the magnetic field strength in Tesla or Gauss.
• Faraday scales measure the effect of a defined magnetic field on a test specimen.
• Cable detectors indicate an induced current flowing through the magnetic field and prevent, for example, a cable is damaged during drilling.
• Electric field meter to measure the electric field strength.

Measuring radioactivity and radiation

• Spectrometer to determine the absorption of a particular wavelength of radiation, but also emission, reflection and photo line spectra
• Dosimeters measure the effect of radiation ( time integral ). often film dosimeters
• Geiger- Müller counter tubes measure the incidence of ionizing particles ( radioactive radiation, X-rays )
• Scintillation counter to measure the incidence of γ - radiation.
• X-ray devices measure the radiation passing through an object.

More

• Marinelli beaker: device for a particular type of measurement of radioactivity.

Derivative instruments

Derivative instruments are developed from the original instruments.

Speed

The rate is the ratio of distance and time.

• The speedometer shows the vehicle at the speed of travel.
• The tachograph records the speed also.
• The log measures the speed in water transport
• The airspeed indicator measures the speed of aircraft.
• The variometer indicates climb or sink rate for aircraft.
• Radar measures the velocity using the Doppler effect generated by a radar transmitter and reflected by the vehicle radar waves.
• Lidar: Lidar stands for light detection and ranging and is one of the radar (radio wave detection and ranging ) related method for remote measurement of atmospheric parameters.
• A laser surface velocimeter measures the feed rate of a product strand in the industry.

Number of revolutions

• Speed ​​measuring device: mechanical or electronic meter, common application in the automotive industry and aircraft, are a statement about the revolutions of a unit (engine, ... ). With a known translation also velocity and also can be determined.
• Gyro: ( historical ) mechanical design for speed determination
• Hall sensor: for speed determination using Hall effect

Acceleration

The acceleration is the change in speed per unit time.

• Acceleration sensors usually measure the force acting on a test body in the accelerated system ( F = ma ).

Distance covered

• Odometers are ( general term ) odometer.
• Odometer measures the distance traveled, car ...
• When a taxi is calculated on the basis of distance and time with a taximeter of the payable fare.
• Helldunkelgeolokator to track the routes of very small birds.

Performance

• Power meter ( wattmeter ) determine electrical power from voltage and current

Measurements of liquids and gases

• Flowmeters measure the mass flow or volume flow An Electromagnetic Flowmeter (MID ) works without moving parts. It calculates the flow rate of an electrically conductive medium on the basis of the resultant by means of induction by a magnetic field externally applied electric voltage.
• Coriolis mass flowmeters utilize the Coriolis force to flow to determine ..
• Hot-wire anemometers measure the cooling of a heated wire and calculate therefrom the flow

• Sonar to determine the depth of water or the find of the active sound objects in the water ( rare in aviation ) see Barcheck a method for calibrating a sonar
• Tensiometers measure the surface tension of a liquid
• Potetometer measure the water consumption of a plant
• PH meter to measure the pH ( acid, alkali ) of a liquid
• Transmissometer in environmental determining the dust content / amount of a gas in air
• Turbidity Meters ( nephelometer ) determine the proportion of particulate solids in a liquid.

Measurements on solids

All instruments for determining the length and density, weight and hardness testing and X-ray machines can also be used for solids.

• Grindometer measure grain sizes.
• Lysimeters measure soil biological, and physical data.
• Tensiometers continuously measure the soil moisture.
• Feuchteabsolutbestimmer measure the moisture content in solids
• SRT pendulum measure the skid resistance of road surfaces.
• Farinograph used for rheological testing of wheat flours

Meteorological Instruments

The following devices are used in meteorology and, of course, but also in other technical fields.

• Barometer to measure the pressure of air and also the height ( altimeter ). About the display of air pressure also used to predict the weather.
• Thermometer to measure the temperature.
• Hygrometer to measure the humidity ( see also coulometric moisture sensor).
• Anemometer to measure the wind speed.
• Lysimeters measure the seepage evaporation ratio → evapotranspiration.
• Netradiometer (also net radiometer ) to measure the global radiation ( meteorology total radiation balance )
• Pyranometer global radiation sensor (Meteorology)
• Albedometer net radiation sensor (Meteorology)
• Windsock shows the wind direction and an approximation of the wind speed at
• Wind direction sensor and the weathercock indicates wind direction
• Cyanometer indicates the color intensity of the blue color of the sky, as a measure of the amount of water which is located in the atmosphere
• Transmissometer measures the sight.
• Pyrheliometer measures the energy of the sun rays
• Evaporimeter measures the evaporation ( evaporation)
• Ceilometer measures the cloud cover and height
• Ombrometer measures the amount of precipitation.
• Sunshine Autograph ( heliograph ) measures the sunshine.

Measuring the amount of light, the brightness or color temperature

• Lux meter to measure the light intensity, which is exposed to the measuring cell.
• Photometer to measure light intensity
• Densitometers are color meters that measure the color values ​​of surfaces.
• PV instruments are multi - measurement devices for solar systems. Are usually measured light intensity and temperature, and calculated the expected energy yield.

Noise and sound level measurement

Sound level meters measure in most cases, the sound pressure level. For this purpose they contain a precision microphone, a high-precision amplification circuit, and a logarithmic display. The sound pressure level is equally well received from all directions, so the position and orientation of the device do not matter. The instruments used in most cases for the determination of noise exposure in the workplace and on the road. Another application is the determination of vibration and noise during operation of technical devices and the study of countermeasures on their effectiveness.

• Peak meters indicate the peak of a sound recording and are used for modulation of the sound recording - sound pressure and voltage.
• Speckle pattern interferometry ( ESPI ), vibration analysis and shape recognition.
• Laser microphone

Combined devices

• Thermohygrograph example, in museums
• Multifunction Environment Meter - Measurement of quantities in environmental, such as temperature, humidity, illuminance, and sound level. These devices are now to be had for little money. Their accuracy is not comparable with quality appliances. Often use in schools or for home applications.

Universal measuring instruments for various electrical quantities

These devices are not designed for a specific application:

• Multimeter: multimeters for voltage ( ~ / =, with appropriate probe for high voltage measurement ), current ( ~ / = ), resistance ( partly Insulation resistance and continuity test ), diode test, gain of PNP / NPN transistors, display the time course of an electrical size ( multinationals with graphic display ), min / max / average display, condenser capacity, temperature (with appropriate sensor), Logic Tester ( level adjustable), setting a voltage / level / current ( sink ) (also temporal profiles of one of the variables can be specified ). Where only the digital technology has combined all measurements and tests in one device. Industrial multimeters are mandatory calibration in a given period. Analog Multimeter: Voltage, current and resistance measurement with a pointer gauge.
• Digital Multimeter: often with interface to PC data acquisition

Quality of the measurements

Measuring instruments manufacturers should provide information about the error limits ( maximum amounts of the instruments deviation of reading from the correct value ).

In electric instrumentation with analog display (eg, analog multimeter), these limits are preferably in % FS ( Percent of full scale ) indicated, often by means of a class character. Thus, the maximum absolute error of measurement is meant; it is calculated over the full scale value. A measuring instrument with a scale value of eg 100 V and a class V = 1.5 may differ even in the best case, up to 1.5% ∙ 100 1.5 V in its display the correct value. This specification applies to the entire measuring range independently of the measured value.

For instruments with digital display measuring instruments see deviation, and digital multimeter.

The relative error limit of a measured value is defined as the absolute error limit divided by the correct value; it is all the greater, the smaller the measured value. For switchable measuring devices, should therefore be selected, the measuring range, with which one to maximize the rash.

Other measurement errors, such as caused by self-consumption or by non sinusoidal waveform when changing variables can not be measured with those listed and must be determined separately.

Analytical instruments

• Chromatographs separate mixtures or determine relative rates of migration of substances in the selected media. The exact name describes the structure: gas chromatograph
• Säulenchromatographen
• Dünnschichtchromatographen

Industrial Metrology, Production Metrology and industrial metrology

These devices are used in most cases to produce a product or serve, for example in the material testing of the quality assurance of the products or the billing for services.

• Coordinate measuring machine universal length measuring instrument in industrial quality inspection
• Typometer are linear scales that are scaled for typesetting
• Coating thickness gauge to determine the thickness of a layer on a support
• Perthometer also profilometer to characterize the roughness of surfaces
• Grindometer for measuring the granularity of a paste or of paints
• Turbidimeter or nephelometer for measurement of the suspension of small particles in a liquid or gas colloid
• Tribometer for determining the friction in bearing materials, inter alia,
• Ductilometer Zugfestigkeitsuntersuchungen
• Universal testing for investigation of mechanical properties such as elastic modulus, yield strength, tensile strength, elongation at break, or maximum pressure force
• A rheometer to measure the vulcanization of Kautschuk-/Gummi-Mischungen

Measurement of material properties

• Tribometer
• Rheometer
• Tensile test

Hardness testing

The hardness measurement, a defined force leads to a permanent deformation of the test specimen or penetration of a test geometry in the test body. The instruments are designated according to the method used. Example: Brinell meter.

• The Poldi hammer is used to measure the hardness of hard materials by means of impact hardness test
• Johan August Brinell hardness test: A ball is pressed into the sample. The diameter of the ball impression is the measure of the Brinellhärtewert HB.
• Rockwell hardness test: A ball or a diamond cone is pushed into the sample. The residual depth of penetration is measured and derived from this value, the Rockwell hardness HRx (x is C ( engl. cone = cone ) when tested with diamond cone and B (English ball = ball ) when tested with diamond ball ).
• Vickers hardness test: The tip of a four-sided pyramid is pressed into the sample. The diagonals of the permanent indentation are measured from the length of which can be the Vickers hardness value HV calculated.

The various methods are differently suitable depending on the type and hardness of the material to be tested.

Standard gauges

Standard instrumentation - are instruments which perform a number of set in a standard measurements. These are usually also logged a verification to allow for opinions.

The designation of the instruments is done according to the standard.

Example: VDE113 ( EN60204 ) with 10 A - PE test, high voltage test, resistance test and boundary detection, insulation test

Important standard measuring instruments:

• VDE100 General Test for electrical appliances
• VDE113 ( EN60204 ) test for the electrical equipment of machines
• Grounding tester functionality of the foundation earth electrode
• Socket tester Standardised connection ( small section of VDE100 )
• Nachlaufwegmessgerät to determine the case of hydraulic presses to the distance traveled after an emergency stop.

Data and Communication Technology

This standard gauges investigate the correct execution of the cable connections ( connection between connector and cable ) and / or the physics of information technology, ie level of the signal and interference. In industrial applications, these devices are used mainly for fieldbuses or Ethernet. In addition to the testers, so devices that examine the physics, there are protocol analyzers that examine the data content. The list is only an example again some typical devices.

Local buses

• IEC -625 bus ( IEEE -488 )

Fieldbuses

• Profibus Tester: level height data throughput, round trip time, scheduling, slave list
• CAN -Bus Tester: error frames, data throughput,
• AS-Interface Bus Tester: level height, slave list, Slave no. assign

Ethernet

If, due to its distribution system for which there is the greatest number of analysis programs. Here is a small selection without judgment ...

• Ethernet Cabel -Check tester: Thin Ethernet ( RG98U ), Thick Ethernet (yellow cable), RJ45
• MRTG Analysis: Multi Router Traffic Grapher representation of network traffic, among other
• Ethereal or Wireshark analysis: Data Used channels of a network, data, protocols
• Nmap analysis: network scanner with many functions

Normal

Standards are material measures, measuring instruments, reference materials or measuring devices, which have the purpose to determine a unit or one or more variable values ​​, embody, preserve or reproduce in order to pass this to other instruments by comparison. Normal Routinely used hot working standards. Reference standards are, however, used only for occasional calibration of the working standards, and possibly also on other intervening standards, which are then called Normal higher ( second, third ) order. Thus, the burden of the higher order normal is minimized. The reference standards are returned via another calibration hierarchy to a primary standard that meets the highest metrological requirements. This is usually a by a national metrology institute entertaining national standard or an international standard. Within the calibration hierarchy the accuracy of the normal upward steadily.

Test benches are used for error control for quality assurance or calibration of measuring instruments (for example, water meters ).

Custody transfer measurement devices

Instruments whose measurement result is used for the calculation of commercial services (such as balances in the commercial, water meter) must meet verifiable legal requirements. That is, their design shall by the Physikalisch -Technische Bundesanstalt ( PTB) and the devices must be calibrated with a calibration after a certain time by nationally recognized testing laboratories with a method approved by the Bureau of Standards is normally required to be refreshed. The Weights and Measures Act defines calibration error limits that must not be exceeded for various load ranges.

Examples: scales, water meter, gas meter, electric meter, heat meter, fuel meter, flow meter

Example of an exceptionally Allowed non-verifiable measuring instrument subject to: Heat cost allocators

In April 2004, the European Measuring Instruments Directive (MID ) has been published, the implementation must take place in national law by 20 October 2006.

Intrinsically safe instruments

The measuring principle of intrinsically safe or explosion proof instruments is the above-mentioned matter, however, these devices must meet specific requirements for their application that they find, for example, in mining or underground works (chemical) industry. Directives 94/9/EC or ATEX determine how the requirements are checked for electrical, mechanical and material- technical specifications. Approved inspection issue a certificate, which is a prerequisite for commissioning of instruments in the specific hazardous areas upon successful approval.

Medical instruments

For instruments in medicine, special rules apply. You must comply with the provisions of MedGV, the Medical Device Regulation. This applies also be used in the approved medicine for the instruments a) classified as medical devices and b). The field of alternative medicine remains unaffected. So the Tesla meter, a biofield meter or body fat scales are not covered by the regulations.

• Actometer for detecting the motion activity
• Ergometer measures the physical work or performance
• Sphygmomanometer was so often historically connected by the Riva Rocci sphygmomanometer with developed, in which you could manually determine with cuff systolic blood pressure. Nowadays, however, is usually not measured manually with mercury but oscillometrically with digital display. In addition to these bloodless measurement method, there are still clinical procedures in which blood pressure is measured in a blood vessel directly via a pressure transducer. See blood pressure measurement.
• Blood Glucose Meter - This is an important device for diabetes patients. With it, the current value of * glucose level in blood is determined. In addition to the classical method, in which a drop of blood is needed, there are also newer approaches of measuring instruments allow a unblutigte measurement.
• ECG devices are medical devices for displaying and recording the sum of the electrical activity of the heart.
• EEG devices are medical devices for display and recording of measurable from outside electrical activity of the brain
• Clinical thermometer to measure the ( human) body temperature
• Capnometer capnograph to measure the carbon dioxide content of the air exhaled by a patient and monitor.
• Body fat scale is next to the body weight with the percentage of body fat.
• Scoliometer measure inclination angle of the back surface to the horizontal.
• Spirometer to check lung function.

Assistive for measurements in medicine

Assistive for measurements in medicine are not really measuring devices, but are used for measurements:

• Microscope, especially light microscopes eg for counting / detection of bacteria ...
• Medical cameras ( some with infrared or ultraviolet light )
• Ultrasound diagnostic equipment (pregnancy, ... )
• X-ray diagnostic equipment (internal organs, bone fractures, osteoporosis ... )
• Parallelometer for measuring Disparallelitäten in the manufacture of dentures

Comments

• In the classification by the technical principle, after indicating the meter, in the article display (technology) is received; here is only mentioned what size is measured.
• In some cases, the term sensor or encoder (the measurement by leading part ) equated with the meter. When selecting a device or method is to look maybe by this reference.
• Out of Specification ( OOS) means that a measured value is outside the calibrated range of the meter is located.