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| Please improve this article if you can.Other sensors, such as a thermocouple, produce an output voltage or other electrical output which may be attached to a meter for reading a change or interpreted by another device (such as a computer).For accuracy in the application a calibration of the sensor and its output information is necessary.There are also innumerable applications for sensors of which most people are never aware.Sensors that measure very small changes must have very high sensitivities.Technological progress allows more and more sensors to be manufactured on a microscopic scale as microsensors using MEMS technology.In most cases, a microsensor reaches a significantly higher speed and sensitivity compared with macroscopic approaches.See also MEMS sensor generations.Classification of measurement errors
2.Types
Because sensors are a type of transducer, they change one form of energy into another.For this reason, sensors can be classified according to the type of energy transfer that they detect.Used in modern surveying equipment, a short pulse of light is emitted and returned by a retroreflector.The adjustment is used to determine distance.Interference fringes between transmitted and reflected lightwaves produced by a coherent source such as a laser are counted and the distance is calculated.Capable of extremely high precision.Particle detector, scintillator, Wire chamber, cloud chamber, bubble chamber.Used in mid 20th century polaroid cameras and applied also to robotics.The gray code is a mutated pattern that ensures that only one bit of information changes with each measured step, thus avoiding ambiguities.Two photocells detecting light passing through the mask can determine a partial revolution of the mask and the direction of that rotation.Classification of measurement errors
A good sensor obeys the following rules:
the sensor should be sensitive to the measured property
the sensor should be insensitive to any other property
the sensor should not influence the measured property
Ideal sensors are designed to be linear.The output signal of such a sensor is linearly proportional to the value of the measured property.The sensitivity is then defined as the ratio between output signal and measured property.If the sensor is not ideal, several types of deviations can be observed:
The sensitivity may in practice differ from the value specified.This is called a sensitivity error, but the sensor is still linear.If the output signal is not zero when the measured property is zero, the sensor has an offset or bias.This is defined as the output of the sensor at zero input.If the sensitivity is not constant over the range of the sensor, this is called nonlinearity.Usually this is defined by the amount the output differs from ideal behavior over the full range of the sensor, often noted as a percentage of the full range.Often, this behaviour is described with a bode plot showing sensitivity error and phase shift as function of the frequency of a periodic input signal.Long term drift usually indicates a slow degradation of sensor properties over a long period of time.Hysteresis is an error caused by when the measured property reverses direction, but there is some finite lag in time for the sensor to respond, creating a different offset error in one direction than in the other.If the sensor has a digital output, the output is essentially an approximation of the measured property.The approximation error is also called digitization error.If the signal is monitored digitally, limitation of the sampling frequency also can cause a dynamic error.The sensor may to some extent be sensitive to properties other than the property being measured.For example, most sensors are influenced by the temperature of their environment.All these deviations can be classified as systematic errors or random errors.Systematic errors can sometimes be compensated for by means of some kind of calibration strategy.Noise is a random error that can be reduced by signal processing, such as filtering, usually at the expense of the dynamic behaviour of the sensor.Resolution
The resolution of a sensor is the smallest change it can detect in the quantity that it is measuring.Often in a digital display, the least significant digit will fluctuate, indicating that changes of that magnitude are only just resolved.The resolution is related to the precision with which the measurement is made.For example, a scanning probe (a fine tip near a surface collects an electron tunnelling current) can resolve atoms and molecules.Biological sensors
All living organisms contain biological sensors with functions similar to those of the mechanical devices described.Artificial sensors that mimic biological sensors by using a biological sensitive component, are called biosensors.The human senses are examples of specialized neuronal sensors.Actuator
Car sensor: reversing sensor and rain sensor.Look up Sensor in
Wiktionary, the free dictionary.Overview of Sensors and Needs for Environmental Monitoring.Other sensors, such as a thermocouple, produce an output voltage or other electrical output which may be attached to a meter for reading a change or interpreted by another device (such as a computer).For accuracy in the application a calibration of the sensor and its output information is necessary.There are also innumerable applications for sensors of which most people are never aware.Applications include automobiles, machines, aerospace, medicine, industry, and robotics.Sensors that measure very small changes must have very high sensitivities.Technological progress allows more and more sensors to be manufactured on a microscopic scale as microsensors using MEMS technology.In most cases, a microsensor reaches a significantly higher speed and sensitivity compared with macroscopic approaches.See also MEMS sensor generations.Non Initialized systems
1.Types
Because sensors are a type of transducer, they change one form of energy into another.For this reason, sensors can be classified according to the type of energy transfer that they detect.Capable of extremely high precision.Even older systems like Fathometers (and fish finders) and other 'Tactical Active' Sonar (Sound Navigation And Ranging) systems in naval applications which mostly use audible sound frequencies.The gray code is a mutated pattern that ensures that only one bit of information changes with each measured step, thus avoiding ambiguities.Initialized systems
These require starting from a known distance and accumulate incremental changes in measurements.Two photocells detecting light passing through the mask can determine a partial revolution of the mask and the direction of that rotation.Classification of measurement errors
A good sensor obeys the following rules:
the sensor should be sensitive to the measured property
the sensor should be insensitive to any other property
the sensor should not influence the measured property
Ideal sensors are designed to be linear.The output signal of such a sensor is linearly proportional to the value of the measured property.The sensitivity is then defined as the ratio between output signal and measured property.If the sensor is not ideal, several types of deviations can be observed:
The sensitivity may in practice differ from the value specified.This is called a sensitivity error, but the sensor is still linear.Since the range of the output signal is always limited, the output signal will eventually reach a minimum or maximum when the measured property exceeds the limits.If the output signal is not zero when the measured property is zero, the sensor has an offset or bias.This is defined as the output of the sensor at zero input.If the sensitivity is not constant over the range of the sensor, this is called nonlinearity.Usually this is defined by the amount the output differs from ideal behavior over the full range of the sensor, often noted as a percentage of the full range.If the deviation is caused by a rapid change of the measured property over time, there is a dynamic error.Often, this behaviour is described with a bode plot showing sensitivity error and phase shift as function of the frequency of a periodic input signal.If the output signal slowly changes independent of the measured property, this is defined as drift.Long term drift usually indicates a slow degradation of sensor properties over a long period of time.Hysteresis is an error caused by when the measured property reverses direction, but there is some finite lag in time for the sensor to respond, creating a different offset error in one direction than in the other.If the sensor has a digital output, the output is essentially an approximation of the measured property.The approximation error is also called digitization error.If the signal is monitored digitally, limitation of the sampling frequency also can cause a dynamic error.The sensor may to some extent be sensitive to properties other than the property being measured.For example, most sensors are influenced by the temperature of their environment.Noise is a random error that can be reduced by signal processing, such as filtering, usually at the expense of the dynamic behaviour of the sensor.Resolution
The resolution of a sensor is the smallest change it can detect in the quantity that it is measuring.For example, a scanning probe (a fine tip near a surface collects an electron tunnelling current) can resolve atoms and molecules.Biological sensors
All living organisms contain biological sensors with functions similar to those of the mechanical devices described.Artificial sensors that mimic biological sensors by using a biological sensitive component, are called biosensors.The human senses are examples of specialized neuronal sensors.It includes the use of instruments such as total stations, levels and global navigation satellite system receivers.Actuator
Car sensor: reversing sensor and rain sensor.Look up Sensor in
Wiktionary, the free dictionary.Ho, Alex Robinson, David R.Overview of Sensors and Needs for Environmental Monitoring.This page was last modified 14:33, 17 January 2008.See Copyrights for details.Sensors Insights Blog Sensor Technology Alert .SENSORS WEEKLYThe Value of Error Analysis
A big part of selecting the right sensor is matching the device's measurement uncertainty with the accuracy demanded by your application.Here, you decide if a particular sensor meets your measurement requirements.The Right Sensor
No sensor manufacturer offers more styles and variations.Single Source Manufacturing
Minco builds sensors from start to finish.That gives us complete control over product quality, plus flexibility in adapting designs to customer requirements.Minco has designed over 7000 custom sensors, each with unique features for better performance at a lower price.Let our engineers suggest innovative ideas to tailor a sensor to your application.Quality Above AllMinco sensors have proven their reliability in the most critical areas.So do nuclear plant safety systems, rocket motors, power generators, missiles, and calibration labs.Minco is certified to ISO 9001: 2000.According to ISO 4 regulations, the abbreviated title is
SENSORS.Sensors is
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Abstracts, Analytical
Abstracts, Science
Citation Index Expanded, Chemistry
Citation Index, INSPEC, Scopus and Google Scholar.Sensors 2007, 7)
19 December 2007: ...The
authors recognize that the Sensors journal is a world leading journal
that publishes the newest and the most advanced technologies in the
research field of sensors and their related applications.Imagers", to
the journal of Sensors.Air Jiang, Associate Professor, Ph.Published: 31 October 200714 November 2007: Thanks
again for all the help.To be published
continuously until the deadline and papers will be listed
together
at the special websites.Synthetic Aperture Radar (SAR)
Guest Editor: Prof.Marketplace crunches more than one thousand health inspection reports from across the country, and makes a startling discovery.Watch the story, then read about what Sensor Wireless has to offer the Foodservice Industry.Sensor Wireless has designed wireless sensor technology custom suited to meet your needs.Owning a made to specification, wireless sensor device that instantly and seamlessly detect the most miniscule of flaws among the thousands of products it is surrounded by can reduce waste and costly shut downs.Having the power to instantly control the quality of a commodity halfway around the world can improve your supply chain.Where Active Wireless Sensor Technology (AWS) starts, Global VU Enterprise Software takes off.This product gives you the information you need to correct the problem areas within your filling lines for maximum waste reduction.Processors deduct for it, consumers hate it.Reduce bruised produce and improve handling procedures.Pinpoint (bruised produce), monitor (produce bruise monitor) and validate where damage is occurring throughout the supply chain with our produce bruise monitor.All other digital camera sensors only measure the
brightness of each pixel.These approximations reduce image sharpness, which
is not the case with Foveon sensors.Also, the technology is in a more mature stage and many
refinements have been made to increase image quality.Coupled Device) sensors, the pixel measurements are processed
sequentially by circuitry surrounding the sensor, while in APS (Active Pixel
Sensors) the pixel measurements are processed simultaneously by circuitry within
the sensor pixels and on the sensor itself.Capturing images with CCD and APS
sensors is similar to image generation on CRT and LCD monitors respectively.The most common type of APS is the CMOS (Complementary Metal Oxide Semiconductor)
sensor.The earlier mentioned Foveon sensors
are also based on CMOS technology.Nikon's new JFET LBCAST sensor is an APS using
JFET (Junction Field Effect Transistor) instead of CMOS transistors.See also Sensor Sizes, Effective Pixels, Pixels, and Pixel Quality.Schneider Electric recognizes that its commitment does not end with the sale of a sensor.Speak with a Sensor Support Specialist!Osiprox Inductive Cylindrical Sensors for the Food, Beverage and Pharmaceutical Market
Osiprox sensors meet the demands of the aggressive environments involved in these industries such as extreme temperatures and humidity, resistance to food and beverage products and equipment washdowns using chemical agents with IP67, IP68 and IP69 ratings equivalent with industry standards.Find a sensor distributor in your local area.Search competitor sensors to find the Schneider Electric equivalent.Sensor Competency Center supports Telemecanique and Hyde Park sensors of all types.SC906 Analog Series
View More...In late 2006, Telemecanique will be obsoleting select legacy inductive proximity sensors and will be replacing them with a newer line of products.The most common proximity sensors that will be affected are part numbers beginning with XS1 through XS3.Click here to learn more...Schneider Electric Sensor Competency Center Announces Osiprox Basic Series Inductive Sensor Line by TelemecaniqueView News Archives...Company Profile
MTS Systems Corporation (NASDAQ: MTSC) is a global supplier of mechanical testing systems and position sensors for a wide variety of markets and applications.The Sensors Division was created by MTS Systems when it acquired Temposonics, Inc.All rights reserved in all media. |
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