Analyser
Encyclopedia
An analyser, also spelt analyzer, is a person or device that analyses given data. It examines in detail the structure
of the given data and tries to find pattern
s and relationships between parts of the data. An analyser can be a piece of hardware
or a software program running on a computer
.
An analyser can also be an instrument or device which conducts chemical analysis (or similar analysis) on samples or sample streams. Such samples consist of some type of matter such as solid
, liquid
, or gas
. Many analysers perform such analyses automatically or mostly automatically, such as autoanalysers.
such as a chemical process
. Analysers connected to a such a process which conduct automatic sampling can be called online (or on-line) analysers or sometimes inline (or in-line) analysers. For inline analysis, a sensor can be placed in a process vessel or stream of flowing material to conduct the analysis. Another method of online analysis is allowing a sample stream to flow from the process equipment into an analyser, sometimes conditioning the sample stream in between such as reducing pressure
or changing the sample temperature
. Such sampling is typically for fluid
s (either liquids or gases). If the sample stream is not substantially modified by the analyser, it can be returned to the process. Otherwise, the sample stream is not returned; for example, if any reagent
s have been added for the analysis.
The pressure of a sample stream can be lowered by a pressure reducing valve
, particularly since many analysers are not designed to withstand high pressure. Such pressure reducing or similar valves may be used to control the flow rate to the online analyser. If the process pressure is insufficient to allow a sample stream to flow by itself to the analyser, a small pump
may be used to move it there. The temperature of a hot sample may be lowered by use of an online sample cooler. The sampling and analysis can be done at the command of an operator, periodically (for example, every 15 minutes), or continuously - providing an analysis result vs. time graph
on a chart recorder
, computer, or other device. For periodic sampling, valve
s (or other devices) can be switched open to allow a fluid sample stream to flow to the analyser and shut when not sampling.
Some methods of inline analysis are so simple, such as electrical conductivity or pH
, the instruments are usually not even called analysers. Salinity
determined from simple online analysis is often determined from a conductivity measurement where the output signal is calibrated in terms of salinity concentration (for example ppm of NaCl
). Various types of other analyses can be devised. Physical properties can include electrical conductivity (or effectively electrical resistivity
), refractive index
, and radioactivity
measurement. Rather simple processes which use inline electrical conductivity determination are water purification
processes which test how effectively salts have been removed from the output water. Variations of electrical conductivity measurement of solution
s include cation and anion conductivity. Chromatography
such as ion chromatography or HPLC
often tests the output stream continuously by determination of electrical conductivity, particularly cation or anion conductivity, refractive index, colorimetry
or ultraviolet/visible absorbance at a certain wavelength
. Inline sensors for dissolved oxygen
in water are available. There are online and offline analysers available for various other types of analyte
s. Many of these add reagents to the samples or sample streams.
Structure
Structure is a fundamental, tangible or intangible notion referring to the recognition, observation, nature, and permanence of patterns and relationships of entities. This notion may itself be an object, such as a built structure, or an attribute, such as the structure of society...
of the given data and tries to find pattern
Pattern
A pattern, from the French patron, is a type of theme of recurring events or objects, sometimes referred to as elements of a set of objects.These elements repeat in a predictable manner...
s and relationships between parts of the data. An analyser can be a piece of hardware
Hardware
Hardware is a general term for equipment such as keys, locks, hinges, latches, handles, wire, chains, plumbing supplies, tools, utensils, cutlery and machine parts. Household hardware is typically sold in hardware stores....
or a software program running on a computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
.
An analyser can also be an instrument or device which conducts chemical analysis (or similar analysis) on samples or sample streams. Such samples consist of some type of matter such as solid
Solid
Solid is one of the three classical states of matter . It is characterized by structural rigidity and resistance to changes of shape or volume. Unlike a liquid, a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire volume available to it like a...
, liquid
Liquid
Liquid is one of the three classical states of matter . Like a gas, a liquid is able to flow and take the shape of a container. Some liquids resist compression, while others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly...
, or gas
Gas
Gas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
. Many analysers perform such analyses automatically or mostly automatically, such as autoanalysers.
Chemical or substance analysers
The analysis can be done on samples which the operator brings to the analyser or the analyser can be connected to the source of the samples and the sampling be done automatically. The source of samples for automatic sampling is commonly some kind of processProcess (engineering)
In engineering a process is a set of interrelated tasks that, together, transform inputs into outputs. These tasks may be carried out by people, nature, or machines using resources; so an engineering process must be considered in the context of the agents carrying out the tasks, and the resource...
such as a chemical process
Chemical process
In a "scientific" sense, a chemical process is a method or means of somehow changing one or more chemicals or chemical compounds. Such a chemical process can occur by itself or be caused by somebody. Such a chemical process commonly involves a chemical reaction of some sort...
. Analysers connected to a such a process which conduct automatic sampling can be called online (or on-line) analysers or sometimes inline (or in-line) analysers. For inline analysis, a sensor can be placed in a process vessel or stream of flowing material to conduct the analysis. Another method of online analysis is allowing a sample stream to flow from the process equipment into an analyser, sometimes conditioning the sample stream in between such as reducing pressure
Pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
or changing the sample temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
. Such sampling is typically for fluid
Fluid
In physics, a fluid is a substance that continually deforms under an applied shear stress. Fluids are a subset of the phases of matter and include liquids, gases, plasmas and, to some extent, plastic solids....
s (either liquids or gases). If the sample stream is not substantially modified by the analyser, it can be returned to the process. Otherwise, the sample stream is not returned; for example, if any reagent
Reagent
A reagent is a "substance or compound that is added to a system in order to bring about a chemical reaction, or added to see if a reaction occurs." Although the terms reactant and reagent are often used interchangeably, a reactant is less specifically a "substance that is consumed in the course of...
s have been added for the analysis.
The pressure of a sample stream can be lowered by a pressure reducing valve
Valve
A valve is a device that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category...
, particularly since many analysers are not designed to withstand high pressure. Such pressure reducing or similar valves may be used to control the flow rate to the online analyser. If the process pressure is insufficient to allow a sample stream to flow by itself to the analyser, a small pump
Pump
A pump is a device used to move fluids, such as liquids, gases or slurries.A pump displaces a volume by physical or mechanical action. Pumps fall into three major groups: direct lift, displacement, and gravity pumps...
may be used to move it there. The temperature of a hot sample may be lowered by use of an online sample cooler. The sampling and analysis can be done at the command of an operator, periodically (for example, every 15 minutes), or continuously - providing an analysis result vs. time graph
Graphics
Graphics are visual presentations on some surface, such as a wall, canvas, computer screen, paper, or stone to brand, inform, illustrate, or entertain. Examples are photographs, drawings, Line Art, graphs, diagrams, typography, numbers, symbols, geometric designs, maps, engineering drawings,or...
on a chart recorder
Chart recorder
A chart recorder is an electromechanical device that records an electrical or mechanical input trend onto a piece of paper . Chart recorders may record several inputs using different color pens and may record onto strip charts or circular charts...
, computer, or other device. For periodic sampling, valve
Valve
A valve is a device that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category...
s (or other devices) can be switched open to allow a fluid sample stream to flow to the analyser and shut when not sampling.
Some methods of inline analysis are so simple, such as electrical conductivity or pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
, the instruments are usually not even called analysers. Salinity
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
determined from simple online analysis is often determined from a conductivity measurement where the output signal is calibrated in terms of salinity concentration (for example ppm of NaCl
Sodium chloride
Sodium chloride, also known as salt, common salt, table salt or halite, is an inorganic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...
). Various types of other analyses can be devised. Physical properties can include electrical conductivity (or effectively electrical resistivity
Resistivity
Electrical resistivity is a measure of how strongly a material opposes the flow of electric current. A low resistivity indicates a material that readily allows the movement of electric charge. The SI unit of electrical resistivity is the ohm metre...
), refractive index
Refractive index
In optics the refractive index or index of refraction of a substance or medium is a measure of the speed of light in that medium. It is expressed as a ratio of the speed of light in vacuum relative to that in the considered medium....
, and radioactivity
Radioactive decay
Radioactive decay is the process by which an atomic nucleus of an unstable atom loses energy by emitting ionizing particles . The emission is spontaneous, in that the atom decays without any physical interaction with another particle from outside the atom...
measurement. Rather simple processes which use inline electrical conductivity determination are water purification
Water purification
Water purification is the process of removing undesirable chemicals, materials, and biological contaminants from contaminated water. The goal is to produce water fit for a specific purpose...
processes which test how effectively salts have been removed from the output water. Variations of electrical conductivity measurement of solution
Solution
In chemistry, a solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is dissolved in another substance, known as a solvent. The solvent does the dissolving.- Types of solutions :...
s include cation and anion conductivity. Chromatography
Chromatography
Chromatography is the collective term for a set of laboratory techniques for the separation of mixtures....
such as ion chromatography or HPLC
High-performance liquid chromatography
High-performance liquid chromatography , HPLC, is a chromatographic technique that can separate a mixture of compounds and is used in biochemistry and analytical chemistry to identify, quantify and purify the individual components of the mixture.HPLC typically utilizes different types of stationary...
often tests the output stream continuously by determination of electrical conductivity, particularly cation or anion conductivity, refractive index, colorimetry
Colorimetry
Colorimetry is "the science and technology used to quantify and describe physically the human color perception."It is similar to spectrophotometry, but is distinguished by its interest in reducing spectra to the physical correlates of color perception, most often the CIE 1931 XYZ color space...
or ultraviolet/visible absorbance at a certain wavelength
Wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
. Inline sensors for dissolved oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
in water are available. There are online and offline analysers available for various other types of analyte
Analyte
An analyte, or component , is a substance or chemical constituent that is of interest in an analytical procedure. Grammatically, it is important to note that experiments always seek to measure properties of analytes—and that analytes themselves can never be measured. For instance, one cannot...
s. Many of these add reagents to the samples or sample streams.
Types of analysers
- Automated analyserAutomated analyserAn automated analyser is a medical laboratory instrument designed to measure different chemicals and other characteristics in a number of biological samples quickly, with minimal human assistance....
- Bus analyserBus analyzerA bus analyzer is a computer bus analysis tool, often a combination of hardware and software, used during development of hardware or device drivers for a specific bus, for diagnosing bus or device failures, or reverse engineering....
- Differential analyserDifferential analyserThe differential analyser is a mechanical analogue computer designed to solve differential equations by integration, using wheel-and-disc mechanisms to perform the integration...
– early analogue computer - Electron microprobeElectron microprobeAn electron microprobe , also known as an electron probe microanalyzer or electron micro probe analyzer , is an analytical tool used to non-destructively determine the chemical composition of small volumes of solid materials...
- Lexical analyserLexical analysisIn computer science, lexical analysis is the process of converting a sequence of characters into a sequence of tokens. A program or function which performs lexical analysis is called a lexical analyzer, lexer or scanner...
- Logic analyserLogic analyzerA logic analyzer is an electronic instrument which displays signals in a digital circuit. A logic analyzer may convert the captured data into timing diagrams, protocol decodes, state machine traces, assembly language, or correlate assembly with source-level software.Presently, there are three...
- Network analyserNetwork analyzer (electrical)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...
- Protocol analyserPacket snifferA packet analyzer is a computer program or a piece of computer hardware that can intercept and log traffic passing over a digital network or part of a network...
(packet sniffer) - Quadrupole mass analyserQuadrupole mass analyzerThe quadrupole mass analyzer is one type of mass analyzer used in mass spectrometry. As the name implies, it consists of 4 circular rods, set parallel to each other. In a quadrupole mass spectrometer the quadrupole is the component of the instrument responsible for filtering sample ions, based on...
- Spectrum analyserSpectrum analyzerA spectrum analyzer measures the magnitude of an input signal versus frequency within the full frequency range of the instrument. The primary use is to measure the power of the spectrum of known and unknown signals...
- Vector signal analyserVector signal analyzerA vector signal analyzer is an instrument that measures the magnitude and phase of the input signal at a single frequency within the IF bandwidth of the instrument...