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Ananalyser (British English) oranalyzer (American English; seespelling differences) is a tool used to analyze data. For example, a gas analyzer[1] tool is used to analyze gases. It examines the given data and tries to find patterns and relationships. An analyser can be a piece of hardware or software.
Autoanalysers are machines that perform their work with little human involvement.
Analysis can be done directly on samples or the analyser can process data acquired from a remote sensor. The source of samples for automatic sampling is commonly some kind of industrialprocess. Analysers that are connected to a process and conduct automatic sampling, can be calledonline (oron-line)analysers or sometimesinline (orin-line)analysers. For inline analysis, a sensor can be placed in a process vessel or stream of flowing material. Another method of online analysis is allowing a sample stream to flow from the process equipment into an analyser, sometimes conditioning the sample stream e.g., by reducingpressure or changing the sampletemperature. Many analysers are not designed to withstand high pressure. Such sampling is typically forfluids (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 discarded; for example, ifreagents were added.
Pressure can be lowered by a pressure reducingvalve. Such valves may be used to control theflow rate[which?] to the online analyser. The temperature of a hot sample may be lowered by use of an online sample cooler. Analysis can be done periodically (for example, every 15 minutes), or continuously. For periodic sampling,valves (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 aselectrical conductivity orpH, 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 exampleppm ofNaCl). Various types of other analyses can be devised. Physical properties can includeelectrical conductivity (or effectivelyelectrical resistivity),refractive index, andradioactivity measurement. Simple processes that use inlineelectrical conductivity determination arewater purification processes which test how effectivelysalts have been removed from the output water. Electrical conductivity variations includecation andanion conductivity.Chromatography such asion chromatography orHPLC often tests the output stream continuously by measuring electrical conductivity, particularly cation or anion conductivity, refractive index,colorimetry orultraviolet/visibleabsorbance at a certainwavelength. InlineOnline and offline analysers are available for other types ofanalytes. Many of these add reagents to the samples or sample streams.