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2,700 | Instrument error refers to the error of a measuring instrument, or the difference between the actual value and the value indicated by the instrument. There can be errors of various types, and the overall error is the sum of the individual errors.
Types of errors include
systematic errors
random errors
absolute error
other error
Systematic errors
The size of the systematic error is sometimes referred to as the accuracy | Instrument error |
2,701 | Instrumentation is a collective term for measuring instruments, used for indicating, measuring and recording physical quantities. It is also a field of study about the art and science about making measurement instruments, involving the related areas of metrology, automation, and control theory.
The term has its origins in the art and science of scientific instrument-making | Instrumentation |
2,702 | Instrumentation and control engineering (ICE) is a branch of engineering that studies the measurement and control of process variables, and the design and implementation of systems that incorporate them. Process variables include pressure, temperature, humidity, flow, pH, force and speed.
ICE combines two branches of engineering | Instrumentation and control engineering |
2,703 | Instrumentation is used to monitor and control the process plant in the oil, gas and petrochemical industries. Instrumentation ensures that the plant operates within defined parameters to produce materials of consistent quality and within the required specifications. It also ensures that the plant is operated safely and acts to correct out of tolerance operation and to automatically shut down the plant to prevent hazardous conditions from occurring | Instrumentation in petrochemical industries |
2,704 | An integrating ADC is a type of analog-to-digital converter that converts an unknown input voltage into a digital representation through the use of an integrator. In its basic implementation, the dual-slope converter, the unknown input voltage is applied to the input of the integrator and allowed to ramp for a fixed time period (the run-up period). Then a known reference voltage of opposite polarity is applied to the integrator and is allowed to ramp until the integrator output returns to zero (the run-down period) | Integrating ADC |
2,705 | An ion drift meter is a device used to measure the velocity of individual ions in the area of a spacecraft. This information can then be used to calculate the ion drift in the space surrounding the instrument as well as the strength of an electric field present, provided that the magnetic field strength has been determined using a magnetometer. The device itself works by allowing ions to pass through an opening at the front of the instrument and measuring the currents produced by the impacts of ions in different locations on a grid at the back | Ion drift meter |
2,706 | An ion-sensitive field-effect transistor (ISFET) is a field-effect transistor used for measuring ion concentrations in solution; when the ion concentration (such as H+, see pH scale) changes, the current through the transistor will change accordingly. Here, the solution is used as the gate electrode. A voltage between substrate and oxide surfaces arises due to an ion sheath | ISFET |
2,707 | An ion-sensitive field-effect transistor (ISFET) is a field-effect transistor used for measuring ion concentrations in solution; when the ion concentration (such as H+, see pH scale) changes, the current through the transistor will change accordingly. Here, the solution is used as the gate electrode. A voltage between substrate and oxide surfaces arises due to an ion sheath | ISFET |
2,708 | An ion-sensitive field-effect transistor (ISFET) is a field-effect transistor used for measuring ion concentrations in solution; when the ion concentration (such as H+, see pH scale) changes, the current through the transistor will change accordingly. Here, the solution is used as the gate electrode. A voltage between substrate and oxide surfaces arises due to an ion sheath | ISFET |
2,709 | A kamal, often called simply khashaba (wood in Arabic), is a celestial navigation device that determines latitude. The invention of the kamal allowed for the earliest known latitude sailing, and was thus the earliest step towards the use of quantitative methods in navigation. It originated with Arab navigators of the late 9th century, and was employed in the Indian Ocean from the 10th century | Kamal (navigation) |
2,710 | The Karatmeter is a scientific instrument which uses X-rays to give an exact reading of the purity of gold. The Karatmeter is also referred to as a X-Ray fluorescence (XRF) spectrometer. Due to its very high precision and fast result, X-ray analysis has been adopted by international agencies in India as part of the certification process used to hallmark gold | Karatmeter |
2,711 | A Kelvin bridge, also called a Kelvin double bridge and in some countries a Thomson bridge, is a measuring instrument used to measure unknown electrical resistors below 1 ohm. It is specifically designed to measure resistors that are constructed as four terminal resistors.
Background
Resistors above about 1 ohm in value can be measured using a variety of techniques, such as an ohmmeter or by using a Wheatstone bridge | Kelvin bridge |
2,712 | The Kelvin-Varley voltage divider, named after its inventors William Thomson, 1st Baron Kelvin and Cromwell Fleetwood Varley, is an electronic circuit used to generate an output voltage as a precision ratio of an input voltage, with several decades of resolution. In effect, the Kelvin–Varley divider is an electromechanical precision digital-to-analog converter.
The circuit is used for precision voltage measurements in calibration and metrology laboratories | Kelvin–Varley divider |
2,713 | A Kibble balance is an electromechanical measuring instrument that measures the weight of a test object very precisely by the electric current and voltage needed to produce a compensating force. It is a metrological instrument that can realize the definition of the kilogram unit of mass based on fundamental constants. It was originally called the watt balance because the weight of the test mass is proportional to the product of current and voltage, which is measured in watts | Kibble balance |
2,714 | Koenig's manometric flame apparatus was a laboratory instrument invented in 1862 by the German physicist Rudolph Koenig, and used to visualize sound waves. It was the nearest equivalent of the modern oscilloscope in the late nineteenth and early twentieth centuries.
Description
The manometric flame apparatus consisted of a chamber which acted in the same way as a modern microphone | Koenig's manometric flame apparatus |
2,715 | A Kofler bench, or Kofler heating bar; Kofler hot bar; Kofler hot bench, in German, Kofler-Heizbank, is a metal strip with a temperature gradient (range room temperature to 300°C). Any substance can be placed on a section of the strip revealing its thermal behaviour at the temperature at that point. The gradient is engineered to be approximately linear | Kofler bench |
2,716 | A hydrometer or lactometer is an instrument used for measuring density or relative density of liquids based on the concept of buoyancy. They are typically calibrated and graduated with one or more scales such as specific gravity.
A hydrometer usually consists of a sealed hollow glass tube with a wider bottom portion for buoyancy, a ballast such as lead or mercury for stability, and a narrow stem with graduations for measuring | Hydrometer |
2,717 | The Langendorff heart or isolated perfused heart assay is an ex vivo technique used in pharmacological and physiological research using animals and also humans. Named after the German physiologist Oskar Langendorff, this technique allows the examination of cardiac contractile strength and heart rate without the complications of an intact animal or human. After more than 100 years, this method is still being used | Langendorff heart |
2,718 | A Langmuir probe is a device used to determine the electron temperature, electron density, and electric potential of a plasma. It works by inserting one or more electrodes into a plasma, with a constant or time-varying electric potential between the various electrodes or between them and the surrounding vessel. The measured currents and potentials in this system allow the determination of the physical properties of the plasma | Langmuir probe |
2,719 | A laser beam profiler captures, displays, and records the spatial intensity profile of a laser beam at a particular plane transverse to the beam propagation path. Since there are many types of lasers — ultraviolet, visible, infrared, continuous wave, pulsed, high-power, low-power — there is an assortment of instrumentation for measuring laser beam profiles. No single laser beam profiler can handle every power level, pulse duration, repetition rate, wavelength, and beam size | Laser beam profiler |
2,720 | A laser Doppler vibrometer (LDV) is a scientific instrument that is used to make non-contact vibration measurements of a surface. The laser beam from the LDV is directed at the surface of interest, and the vibration amplitude and frequency are extracted from the Doppler shift of the reflected laser beam frequency due to the motion of the surface. The output of an LDV is generally a continuous analog voltage that is directly proportional to the target velocity component along the direction of the laser beam | Laser Doppler vibrometer |
2,721 | The scanning laser vibrometer or scanning laser Doppler vibrometer, was first developed by the British loudspeaker company, Celestion, around 1979, further developed in the 1980s, and commercially introduced by Ometron, Ltd around 1986. It is an instrument for rapid non-contact measurement and imaging of vibration. Fields where they are applied include automotive, medical, aerospace, micro system and information technology as well as for quality and production control | Laser scanning vibrometry |
2,722 | A laser surface velocimeter (LSV) is a non-contact optical speed sensor measuring velocity and length on moving surfaces. Laser surface velocimeters use the laser Doppler principle to evaluate the laser light scattered back from a moving object. They are widely used for process and quality control in industrial production processes | Laser surface velocimeter |
2,723 | A laxometer is a measuring device for scalp skin mobility, used in hair restoration surgery, where a strip of skin from a donor area on the back of the scalp is transplanted.
History
The laxometer was first presented at the 15th Annual Meeting of the International Society of Hair Restoration Surgery in Las Vegas. It was invented by Parsa Mohebi, M | Laxometer |
2,724 | An LCR meter is a type of electronic test equipment used to measure the inductance (L), capacitance (C), and resistance (R) of an electronic component. In the simpler versions of this instrument the impedance was measured internally and converted for display to the corresponding capacitance or inductance value.
Readings should be reasonably accurate if the capacitor or inductor device under test does not have a significant resistive component of impedance | LCR meter |
2,725 | LEDDAR (Light-Emitting Diode Detection And Ranging) is a proprietary technology owned by LeddarTech. It uses the time of flight of light signals and signal processing algorithms to detect, locate, and measure objects in its field of view.
Technology
The Leddar technology is like a light-based radar that sends very short light pulses of invisible light about 100,000 times per second to actively illuminate an area of interest | Leddar |
2,726 | A lensmeter or lensometer (sometimes even known as focimeter or vertometer), is an ophthalmic instrument. It is mainly used by optometrists and opticians to measure the back or front vertex power of a spectacle lens and verify the correct prescription in a pair of eyeglasses, to properly orient and mark uncut lenses, and to confirm the correct mounting of lenses in spectacle frames. Lensmeters can also verify the power of contact lenses, if a special lens support is used | Lensmeter |
2,727 | A level staff, also called levelling rod, is a graduated wooden or aluminium rod, used with a levelling instrument to determine the difference in height between points or heights of points above a vertical datum.
When used for stadiametric rangefinding, the level staff is called a stadia rod.
Rod construction and materials
Levelling rods can be one piece, but many are sectional and can be shortened for storage and transport or lengthened for use | Level staff |
2,728 | A level staff, also called levelling rod, is a graduated wooden or aluminium rod, used with a levelling instrument to determine the difference in height between points or heights of points above a vertical datum.
When used for stadiametric rangefinding, the level staff is called a stadia rod.
Rod construction and materials
Levelling rods can be one piece, but many are sectional and can be shortened for storage and transport or lengthened for use | Level staff |
2,729 | A Lippmann electrometer is a device for detecting small rushes of electric current and was invented by Gabriel Lippmann in 1873.
The device consists of a tube which is thick on one end and very thin on the other. The thin end is designed to act as a capillary tube | Lippmann electrometer |
2,730 | The color measurement of a liquid is the evaluation of that liquid's color properties. This is usually done through visual means, but can also be done by through automated means. The former provides approximate data, while the latter can provide objective data on the color properties of any given liquid | Liquid color measurement |
2,731 | A load cell converts a force such as tension, compression, pressure, or torque into an electrical signal that can be measured and standardized. It is a force transducer. As the force applied to the load cell increases, the electrical signal changes proportionally | Load cell |
2,732 | A logic probe is a low-cost hand-held test probe used for analyzing and troubleshooting the logical states (boolean 0 or 1) of a digital circuit. When many signals need to be observed or recorded simultaneously, a logic analyzer is used instead.
Overview
While most logic probes are powered by the circuit under test, some devices use batteries | Logic probe |
2,733 | The lunar penetrometer was a spherical electronic tool that served to measure the load-bearing characteristics of the moon in preparation for spacecraft landings. It was designed by NASA to be dropped onto the surface from a vehicle orbiting overhead and transmit information to the spacecraft. However, despite it being proposed for several lunar and planetary missions, the device was never actually fielded by NASA | Lunar penetrometer |
2,734 | A lysimeter (from Greek λύσις (loosening) and the suffix -meter) is a measuring device which can be used to measure the amount of actual evapotranspiration which is released by plants (usually crops or trees). By recording the amount of precipitation that an area receives and the amount lost through the soil, the amount of water lost to evapotranspiration can be calculated.
Lysimeters are of two types: weighing and non-weighing | Lysimeter |
2,735 | A Machmeter is an aircraft pitot-static system flight instrument that
shows the ratio of the true airspeed to the speed of sound,
a dimensionless quantity called Mach number. This is shown on a Machmeter as a decimal fraction.
An aircraft flying at the speed of sound is flying
at a Mach number of one, expressed as Mach 1 | Machmeter |
2,736 | A macrometer is an instrument for measuring the size and distance of distant objects. Distant in this sense means a length that can not be readily measured by a calibrated length. The optical version of this instrument used two mirrors on a common sextant | Macrometer |
2,737 | A magnetic level gauge is a type of level sensor, i. e. , a device used to measure the level of fluids | Magnetic level gauge |
2,738 | Magnetic tweezers (MT) are scientific instruments for the manipulation and characterization of biomolecules or polymers. These apparatus exert forces and torques to individual molecules or groups of molecules. It can be used to measure the tensile strength or the force generated by molecules | Magnetic tweezers |
2,739 | A magnetometer is a device that measures magnetic field or magnetic dipole moment. Different types of magnetometers measure the direction, strength, or relative change of a magnetic field at a particular location. A compass is one such device, one that measures the direction of an ambient magnetic field, in this case, the Earth's magnetic field | Magnetometer |
2,740 | A marine sandglass is a timepiece of simple design that is a relative of the common hourglass, a marine (nautical) instrument known since the 14th century (although reasonably presumed to be of very ancient use and origin). Sandglasses were used to measure the time at sea or on a given navigational course, in repeated measures of small time increments (e. g | Marine sandglass |
2,741 | A mass flow controller (MFC) is a device used to measure and control the flow of liquids and gases. A mass flow controller is designed and calibrated to control a specific type of liquid or gas at a particular range of flow rates. The MFC can be given a setpoint from 0 to 100% of its full scale range but is typically operated in the 10 to 90% of full scale where the best accuracy is achieved | Mass flow controller |
2,742 | Mass interconnect systems act as the connector interface between test instruments (PXI, VXI, LXI, GPIB, SCXI, & PCI) and devices/units under test (D/UUT) and are most often used in defense, aerospace, automotive, manufacturing, and other applications. By mating a receiver on the tester side with an interchangeable test adapter (ITA) on the UUT, a mass interconnect enables the entire system to mate together at one time. Mass interconnect systems are available in multiple sizes and configurations to accommodate virtually any testing requirement | Mass interconnect |
2,743 | Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a mass spectrum, a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures | Mass spectrometry |
2,744 | A Maxwell bridge is a modification to a Wheatstone bridge used to measure an unknown inductance (usually of low Q value) in terms of calibrated resistance and inductance or resistance and capacitance. When the calibrated components are a parallel resistor and capacitor, the bridge is known as a Maxwell bridge. It is named for James C | Maxwell bridge |
2,745 | Medipix is a family of photon counting and particle tracking pixel detectors developed by an international collaboration, hosted by CERN.
Design
These are hybrid detectors as a semiconductor sensor layer is bonded to a processing electronics layer.
The sensor layer is a semiconductor, such as silicon, GaAs, or CdTe in which the incident radiation makes an electron hole/cloud | Medipix |
2,746 | A Megohmmeter or insulation resistance tester, also colloquially known as megger, is a special type of ohmmeter used to measure the electrical resistance of insulators. Insulating components, for example cable jackets, must be tested for their insulation strength at the time of commissioning and as part of maintenance of high voltage electrical equipment and installations.
For this purpose, megohmmeters, which can provide high DC voltages (typically in ranges from 500 V to 5 kV, some are up to 15 kV) at specified current capacity, are used | Megohmmeter |
2,747 | A membrane osmometer is a device used to indirectly measure the number average molecular weight (
M
n
{\displaystyle M_{n}}
) of a polymer sample. One chamber contains pure solvent and the other chamber contains a solution in which the solute is a polymer with an unknown
M
n
{\displaystyle M_{n}}
. The osmotic pressure of the solvent across the semipermeable membrane is measured by the membrane osmometer | Membrane osmometer |
2,748 | A methanometer is an instrument used to measure methane gas in the air of a mine. The Mine Safety Appliances Company Ltd. manufactured the first type - W8 Methanometer around 1950 and it was approved for use by the Ventilation Regulations of 1947 | Methanometer |
2,749 | A microdensitometer is an optical instrument used to measure optical densities in the microscopic domain. A well-known microdensitometer, used in the photographic industry, is a granularity instrument or granularity machine. The granularity measurement involves the use of an optical aperture, 10-50 micrometers in diameter, and in the recording of thousands of optical density readings | Microdensitometer |
2,750 | A microprobe is an instrument that applies a stable and well-focused beam of charged particles (electrons or ions) to a sample.
Types
When the primary beam consists of accelerated electrons, the probe is termed an electron microprobe, when the primary beam consists of accelerated ions, the term ion microprobe is used. The term microprobe may also be applied to optical analytical techniques, when the instrument is set up to analyse micro samples or micro areas of larger specimens | Microprobe |
2,751 | Microwave imaging is a science which has been evolved from older detecting/locating techniques (e. g. , radar) in order to evaluate hidden or embedded objects in a structure (or media) using electromagnetic (EM) waves in microwave regime (i | Microwave imaging |
2,752 | A microwave power meter is an instrument which measures the electrical power at microwave frequencies typically in the range 100 MHz to 40 GHz.
Usually a microwave power meter will consist of a measuring head which contains the actual power sensing element, connected via a cable to the meter proper, which displays the power reading. The head may be referred to as a power sensor or mount | Microwave power meter |
2,753 | A millimeter wave scanner is a whole-body imaging device used for detecting objects concealed underneath a person’s clothing using a form of electromagnetic radiation. Typical uses for this technology include detection of items for commercial loss prevention, smuggling, and screening for weapons at government buildings and airport security checkpoints.
It is one of the common technologies of full body scanner used for body imaging; a competing technology is backscatter X-ray | Millimeter wave scanner |
2,754 | Miniflex is an X-ray diffraction (XRD) analytical measuring instrument produced by Rigaku. The current instrument is the fourth in a series introduced in 1973.
The Rigaku MiniFlex is historically significant in that it was the first commercial benchtop (tabletop) X-ray diffraction instrument | Miniflex |
2,755 | A monochord, also known as sonometer (see below), is an ancient musical and scientific laboratory instrument, involving one (mono-) string (chord). The term monochord is sometimes used as the class-name for any musical stringed instrument having only one string and a stick shaped body, also known as musical bows. According to the Hornbostel–Sachs system, string bows are bar zithers (311 | Monochord |
2,756 | A multimeter (also known as a volt-ohm-milliammeter, volt-ohmmeter or VOM) is a measuring instrument that can measure multiple electrical properties. A typical multimeter can measure voltage, resistance, and current, in which case can be used as a voltmeter, ammeter, and ohmmeter. Some feature the measurement of additional properties such as temperature and capacitance | Multimeter |
2,757 | The Murray loop bridge is a bridge circuit used for locating faults in underground or underwater cables. It has been used for more than 100 years but is being replaced by the more precise Time-domain reflectometer.
One end of the faulted cable is connected through a pair of resistors to the voltage source | Murray loop bridge |
2,758 | Electromagnetic near-field scanner (NFS) is a measurement system to determine a spatial distribution of an electrical quantity provided by a single or multiple field probes acquired in the near-field region of a device under test possibly accompanied by the associated numerical post-processing methods enabling a conversion of the measured quantity into electromagnetic field.
Depending on a signal receiver detecting the probe signal, voltage as a function of time or frequency is a typical measured quantity. It should be underlined that as the DUT may be considered any object radiating or storing electromagnetic field energy intentionally or unintentionally, e | Near-field scanner |
2,759 | A nephelometer or aerosol photometer is an instrument for measuring the concentration of suspended particulates in a liquid or gas colloid. A nephelometer measures suspended particulates by employing a light beam (source beam) and a light detector set to one side (often 90°) of the source beam. Particle density is then a function of the light reflected into the detector from the particles | Nephelometer |
2,760 | A network analyzer is an instrument that measures the network parameters of electrical networks. Today, network analyzers commonly measure s–parameters because reflection and transmission of electrical networks are easy to measure at high frequencies, but there are other network parameter sets such as y-parameters, z-parameters, and h-parameters. Network analyzers are often used to characterize two-port networks such as amplifiers and filters, but they can be used on networks with an arbitrary number of ports | Network analyzer (electrical) |
2,761 | A nilometer was a structure for measuring the Nile River's clarity and water level during the annual flood season. There were three main types of nilometers, calibrated in Egyptian cubits: (1) a vertical column, (2) a corridor stairway of steps leading down to the Nile, or (3) a deep well with culvert. If the water level was low, the fertility of the floodplain would suffer | Nilometer |
2,762 | The Ohmer fare register was, in various models, a mechanical device for registering and recording the fares of passengers on streetcars, buses and taxis in the early 20th century. It was invented and improved by members and employees of the Ohmer family of Dayton, Ohio, especially John F. Ohmer who founded the Ohmer Fare Register Company in 1898, and his brother Wilfred I | Ohmer fare register |
2,763 | An oil content meter (OCM) is an integral part of all oily water separator (OWS) systems. Oil content meters are also sometimes referred to as oil content monitors, bilge alarms, or bilge monitors.
OCM technology
The OCM continuously monitors how much oil is in the water that is pumped out the discharge line of the OWS system | Oil content meter |
2,764 | The open metering system of the Open Metering System Group e. V. stands for a manufacturer- and media-independent standardization for Meter-Bus (M-Bus) based communication between utility meters (electricity, gas, water, thermal energy), submetering (cold/hot water, thermal energy, heat cost allocators), and systems in the field of smart meters | Open metering system |
2,765 | The Royal Observer Corps (ROC) was a civil defence organisation operating in the United Kingdom between October 1925 and 31 December 1995, when the Corps' civilian volunteers were stood down. (ROC headquarters staff at RAF Bentley Priory stood down on 31 March 1996). Composed mainly of civilian spare-time volunteers, ROC personnel wore a Royal Air Force (RAF) style uniform and latterly came under the administrative control of RAF Strike Command and the operational control of the Home Office | Operational instruments of the Royal Observer Corps |
2,766 | An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the irradiance of the light but could also, for instance, be the polarization state. The independent variable is usually the wavelength of the light or a unit directly proportional to the photon energy, such as reciprocal centimeters or electron volts, which has a reciprocal relationship to wavelength | Optical spectrometer |
2,767 | The optometer was a device used for measuring the necessary spherical and/or cylindrical corrections to be prescribed for eyeglasses, from the middle of the 18th century until around 1922, when modern instruments were developed. The term, coined in 1738 by W. Porterfield to describe his Scheiner slit optometer, and used for 200 years to describe many different inventions to measure refractive error of the eye, has completely fallen out of usage today as the task of measuring eyes for spectacles is done with modern instruments, such as the phoropter | Optometer (ophthalmic instrument) |
2,768 | The oscillating U-tube is a technique to determine the density of liquids and gases based on an electronic measurement of the frequency of oscillation, from which the density value is calculated. This measuring principle is based on the Mass-Spring Model.
The sample is filled into a container with oscillation capacity | Oscillating U-tube |
2,769 | An oscilloscope (informally scope or O-scope) is a type of electronic test instrument that graphically displays varying voltages of one or more signals as a function of time. The main purpose is capture information on electrical signals for debugging, analysis, or characterization. The displayed waveform can then be analyzed for properties such as amplitude, frequency, rise time, time interval, distortion, and others | Oscilloscope |
2,770 | An osmometer is a device for measuring the osmotic strength of a solution, colloid, or compound.
There are several different techniques employed in osmometry:
Freezing point depression osmometers may also be used to determine the osmotic strength of a solution, as osmotically active compounds depress the freezing point of a solution. This is the most common method in clinical laboratories because it is the most accurate and simple method | Osmometer |
2,771 | An ozone monitor is electronic equipment that monitors for ozone concentrations in the air. The instrument may be used to monitor ozone values for industrial applications or to determine the amount of ambient ozone at ground level and determine whether these values violate National Ambient Air Quality Standards (NAAQS).
The ozone molecule absorbs ultraviolet radiation, and most ozone monitors utilized in regulatory applications use ultraviolet absorption to accurately quantify ozone levels | Ozone monitor |
2,772 | Particle mass analyser is a measurement technique for classifying aerosol particles according to their mass-to-charge ratio.
Techniques exist for classifying (selecting) aerosol particles in the sub 1,000 nm range according to electrical mobility using devices such as differential mobility analysers.
Electrical mobility
In electrical mobility measurement, aerosol particles are classified according to their aerodynamic drag-charge ratio | Particle mass analyser |
2,773 | A peak meter is a type of measuring instrument that visually indicates the instantaneous level of an audio signal that is passing through it (a sound level meter). In sound reproduction, the meter, whether peak or not, is usually meant to correspond to the perceived loudness of a particular signal. The term peak is used to denote the meter's ability, regardless of the type of visual display, to indicate the highest output level at any instant | Peak meter |
2,774 | A pedometer, or step-counter, is a device, usually portable and electronic or electromechanical, that counts each step a person takes by detecting the motion of the person's hands or hips. Because the distance of each person's step varies, an informal calibration, performed by the user, is required if presentation of the distance covered in a unit of length (such as in kilometers or miles) is desired, though there are now pedometers that use electronics and software to automatically determine how a person's step varies. Distance traveled (by walking or any other means) can be measured directly by a GPS receiver | Pedometer |
2,775 | In marine navigation, a pelorus is a reference tool for maintaining bearing of a vessel at sea. It is a "simplified compass" without a directive element, suitably mounted and provided with vanes to permit observation of relative bearings. The instrument was named for one Pelorus, said to have been the pilot for Hannibal, circa 203 BC | Pelorus (instrument) |
2,776 | A penetrometer is a device to test the strength of a material.
Soil
There are many types of penetrometer designed to be used on soil. They are usually round or cone shaped | Penetrometer |
2,777 | A Penning trap is a device for the storage of charged particles using a homogeneous magnetic field and a quadrupole electric field. It is mostly found in the physical sciences and related fields of study as a tool for precision measurements of properties of ions and stable subatomic particles, like for example mass, fission yields and isomeric yield ratios. One initial object of study were the so-called geonium atoms, which represent a way to measure the electron magnetic moment by storing a single electron | Penning trap |
2,778 | The Pensky–Martens closed-cup flash-point test is a test for the determination of the flash point of flammable liquids. It is standardized as ASTM D93, EN ISO 2719 and IP 34 The United States Environmental Protection Agency (EPA) has also published Method 1010A: Test Methods for Flash Point by Pensky-Martens Closed Cup Tester, part of Test Methods for Evaluating Solid Waste, Physical/Chemical Methods, which references the ASTM standard series D93. The Pensky-Martens test is a closed-cup method as opposed to the Cleveland open-cup method | Pensky–Martens closed-cup test |
2,779 | A permanent downhole gauge (PDG) is a pressure and/or temperature gauge permanently installed in an oil or gas well. Typically they are installed in tubing in the well and can measure the tubing pressure or annulus pressure or both. Systems installed in well casing to read formation pressure directly, suspended systems, and systems built in coil (continuous) tubing are also available | Permanent downhole gauge |
2,780 | The permeameter is an instrument for rapidly measuring the electromagnetic permeability of samples of iron or steel with sufficient accuracy for many commercial purposes. The name was first applied by Silvanus P. Thompson to an apparatus devised by himself in 1890, which indicates the mechanical force required to detach one end of the sample, arranged as the core of a straight electromagnet, from an iron yoke of special form; when this force is known, the permeability can be easily calculated | Permeameter |
2,781 | A pH meter is a scientific instrument that measures the hydrogen-ion activity in water-based solutions, indicating its acidity or alkalinity expressed as pH. The pH meter measures the difference in electrical potential between a pH electrode and a reference electrode, and so the pH meter is sometimes referred to as a "potentiometric pH meter". The difference in electrical potential relates to the acidity or pH of the solution | PH meter |
2,782 | A phoropter or refractor is an ophthalmic testing device. It is commonly used by eye care professionals during an eye examination, and contains different lenses used for refraction of the eye during sight testing, to measure an individual's refractive error and determine their eyeglass prescription.
It also is used to measure the patients' phorias and ductions, which are characteristics of binocularity | Phoropter |
2,783 | A phosphoroscope is piece of experimental equipment devised in 1857 by physicist A. E. Becquerel to measure how long it takes a phosphorescent material to stop glowing after it has been excited | Phosphoroscope |
2,784 | A photoionization detector or PID is a type of gas detector.
Typical photoionization detectors measure volatile organic compounds and other gases in concentrations from sub parts per billion to 10 000 parts per million (ppm). The photoionization detector is an efficient and inexpensive detector for many gas and vapor analytes | Photoionization detector |
2,785 | A photoplethysmogram (PPG) is an optically obtained plethysmogram that can be used to detect blood volume changes in the microvascular bed of tissue. A PPG is often obtained by using a pulse oximeter which illuminates the skin and measures changes in light absorption. A conventional pulse oximeter monitors the perfusion of blood to the dermis and subcutaneous tissue of the skin | Photoplethysmogram |
2,786 | A pilot direction indicator or pilot's directional indicator (PDI) is an aircraft instrument used by bombardiers to indicate heading changes to the pilot in order to direct them to the proper location to drop bombs. The PDI is used in aircraft where the pilot and bombardier are physically separated and cannot easily see each other. PDI's typically consist of a dial that is installed in the pilot's instrument set on the main console, with an arrow pointer than can be moved to indicate how far and in what direction to correct the heading | Pilot direction indicator |
2,787 | A pitot tube ( PEE-toh; also pitot probe) measures fluid flow velocity. It was invented by a French engineer, Henri Pitot, in the early 18th century, and was modified to its modern form in the mid-19th century by a French scientist, Henry Darcy. It is widely used to determine the airspeed of aircraft; the water speed of boats; and the flow velocity of liquids, air, and gases in industry | Pitot tube |
2,788 | A plane table (plain table prior to 1830) is a device used in surveying site mapping, exploration mapping, coastal navigation mapping, and related disciplines to provide a solid and level surface on which to make field drawings, charts and maps. The early use of the name plain table reflected its simplicity and plainness rather than its flatness.
"Plane" refers to the table being both flat and levelled (horizontal) | Plane table |
2,789 | A planimeter, also known as a platometer, is a measuring instrument used to determine the area of an arbitrary two-dimensional shape.
Construction
There are several kinds of planimeters, but all operate in a similar way. The precise way in which they are constructed varies, with the main types of mechanical planimeter being polar, linear, and Prytz or "hatchet" planimeters | Planimeter |
2,790 | Plasma diagnostics are a pool of methods, instruments, and experimental techniques used to measure properties of a plasma, such as plasma components' density, distribution function over energy (temperature), their spatial profiles and dynamics, which enable to derive plasma parameters.
Invasive probe methods
Ball-pen probe
A ball-pen probe is novel technique used to measure directly the plasma potential in magnetized plasmas. The probe was invented by Jiří Adámek in the Institute of Plasma Physics AS CR in 2004 | Plasma diagnostics |
2,791 | A plethysmograph is an instrument for measuring changes in volume within an organ or whole body (usually resulting from fluctuations in the amount of blood or air it contains). The word is derived from the Greek "plethysmos" (increasing, enlarging, becoming full), and "graphein" (to write).
Organs studied
Lungs
Pulmonary plethysmographs are commonly used to measure the functional residual capacity (FRC) of the lungs—the volume in the lungs when the muscles of respiration are relaxed—and total lung capacity | Plethysmograph |
2,792 | The backstaff is a navigational instrument that was used to measure the altitude of a celestial body, in particular the Sun or Moon. When observing the Sun, users kept the Sun to their back (hence the name) and observed the shadow cast by the upper vane on a horizon vane. It was invented by the English navigator John Davis, who described it in his book Seaman's Secrets in 1594 | Backstaff |
2,793 | A plumb bob, plumb bob level, or plummet, is a weight, usually with a pointed tip on the bottom, suspended from a string and used as a vertical reference line, or plumb-line. It is a precursor to the spirit level and used to establish a vertical datum. It is typically made of stone, wood, or lead, but can also be made of other metals | Plumb bob |
2,794 | A plurimeter is a hand-held measuring instrument for determining surface area or relative angles between surfaces. The device uses mechanical action for calculating the result, analogous to a slide rule. In modern technology, these results are computed by calculator or computer rather than by mechanical instrument | Plurimeter |
2,795 | A potentiometer is an instrument for measuring voltage or 'potential difference' by comparison of an unknown voltage with a known reference voltage. If a sensitive indicating instrument is used, very little current is drawn from the source of the unknown voltage. Since the reference voltage can be produced from an accurately calibrated voltage divider, a potentiometer can provide high precision in measurement | Potentiometer (measuring instrument) |
2,796 | A potometer' (from Greek ποτό = drunken, and μέτρο = measure), sometimes known as transpirometer, is a device used for measuring the rate of water uptake of a leafy shoot which is almost equal to the water lost through transpiration. The causes of water uptake are photosynthesis and transpiration. The rate of transpiration can be estimated in two ways:
Indirectly - by measuring the distance the water level drops in the graduated tube over a measured length of time | Potometer |
2,797 | Road surface textures are deviations from a planar and smooth surface, affecting the vehicle/tyre interaction. Pavement texture is divided into: microtexture with wavelengths from 0 mm to 0. 5 millimetres (0 | Road texture |
2,798 | Proton-transfer-reaction mass spectrometry (PTR-MS) is an analytical chemistry technique that uses gas phase hydronium reagent ions which are produced in an ion source. PTR-MS is used for online monitoring of volatile organic compounds (VOCs) in ambient air and was developed in 1995 by scientists at the Institut für Ionenphysik at the Leopold-Franzens University in Innsbruck, Austria.
A PTR-MS instrument consists of an ion source that is directly connected to a drift tube (in contrast to SIFT-MS no mass filter is interconnected) and an analyzing system (quadrupole mass analyzer or time-of-flight mass spectrometer) | Proton-transfer-reaction mass spectrometry |
2,799 | In telecommunications, a psophometer is an instrument that measures the perceptible noise of a telephone circuit. The core of the meter is based on a true RMS voltmeter, which measures the level of the noise signal. This was used for the first psophometers, in the 1930s | Psophometer |
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