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Correction: Highland City Council metal detector grant 

Deseret Morning News - Oct 06 11:35 PM
Members of Highland's City Council have voted to accept a grant for $3,100 to add a metal detector to the City Council chambers, which also doubles as the city's courtroom for its justice court. A story published Thursday said the council had not yet voted to accept the grant.

Bomb detector plan for Games 
The Observer - Oct 07 5:01 PM
Explosives detectors may have to be fitted at many of London's sports venues, in Underground trains and in bus depots to minimise the terrorist threat when the capital hosts the Olympics in 2012, according to the Games' chief security adviser.

Highland's City Hall may get a metal detector 
Deseret Morning News - Oct 05 12:38 PM
If Highland's justice court judge has his way, a metal detector will soon guard the entrance to Highland's City Council chambers, a small area that doubles as the city's courtroom.

Firefighters, businesses, civic groups kick off Fire Prevention Week 
Williamson Daily News - Oct 07 10:43 PM
Saturday, October 7, 2006 5:02 PM CDT WILLIAMSON - National Fire Prevention Week kicks off today. This week is a great opportunity for the public to take advantage of fire safety training, fire department tours, and smoke detector giveaways.

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- metal detectors

Contents

  • 1 Overview
  • 2 Types
    • 2.1 Thermal
    • 2.2 Electromagnetic
    • 2.3 Mechanical
    • 2.4 Chemical
    • 2.5 Optical metal detector radar detector and radiation
      • 2.5.1 Ionising radiation
      • 2.5.2 Non-ionising metal detector reviews radiation
    • 2.6 Acoustic
    • 2.7 Other types
      • 2.7.1 Non whites metal detector Initialized systems
      • 2.7.2 Initialized systems
  • 3 Classification whites metal detectors of measurement errors
    • 3.1 Resolution
  • 4 Biological
  • 5 See best radar detector also
  • 6 External smoke detector links
Distinguish from censure and censer and motion detectors censor.

Overview

Most sensors are electrical or electronic, although other types exist. A sensor white metal detectors is a type of transducer. Sensors are bounty hunter metal detectors either direct indicating (e.g. a mercury thermometer or electrical meter) or are paired with an indicator (perhaps indirectly through garrett metal detectors an fisher metal detectors analog to digital converter, a computer and a display) so that the value sensed becomes human readable. In addition to spyware detector other applications, sensors are heavily used in medicine, industry motion detector and robotics. Technical progress allows more and more sensors to be manufactured with MEMS white metal detector technology. In most cases this offers the potential to reach a much higher sensitivity. See also MEMS radiation detectors sensor generations.


Types

Since a lie detector significant change involves an exchange of energy, sensors can be classified according lie detector tests to the type of energy transfer that they detect.

Thermal

  • temperature sensors: thermometers, thermocouples, temperature sensitive resistors (thermistors and tesoro metal detector resistance temperature detectors), bi-metal thermometers and thermostats
  • heat sensors: bolometer, calorimeter

Electromagnetic

  • electrical resistance sensors: ohmmeter, multimeter
  • electrical current sensors: galvanometer, ammeter
  • electrical voltage carbon monoxide detectors sensors: leaf electroscope, voltmeter
  • electrical power sensors: watt-hour meters
  • magnetism sensors: magnetic compass, fluxgate compass, magnetometer, Hall effect device,
  • metal detectors

Mechanical

  • pressure sensors: altimeter, garrett metal detector barometer, barograph, pressure gauge, air speed indicator, rate of climb indicator, variometer
  • gas and liquid flow radar detector reviews sensors: flow sensor, anemometer, flow meter, gas escort radar detector meter, water meter, mass flow sensor
  • mechanical sensors: acceleration sensor, position sensor, selsyn, switch, escort radar detectors strain gauge

Chemical

Chemical sensors detect the presence of compass metal detector manuals specific chemicals or classes of chemicals. Examples include oxygen sensors, also known whites metal detector dealers as lambda sensors, ion-selective electrodes, pH glass electrodes, and redox electrodes.

Optical and radiation

  • electromagnetic time-of-flight. Generate an electromagnetic impulse, gold detector broadcast it, then measure the time a reflected pulse takes to return. Commonly known as tesoro metal detectors - RADAR (Radio Detection And Ranging) are now accompanied by the analogous LIDAR hand held metal detectors (Light Detection And Ranging. See gold detectors following line), all being electromagnetic waves. Acoustic sensors are a special case in that a pressure transducer is used to generate a bat detector compression wave in a fluid medium (air or water)
  • light time-of-flight. cobra radar detectors Used in modern surveying equipment, a short pulse of light is emitted and returned by a retroreflector. metal detectors uk The return time of the pulse is radar detector review proportional to the distance and is related to atmospheric density in cheap metal detectors a predictable way.

Ionising radiation

  • radiation sensors: Geiger counter, dosimeter, gold metal detectors Scintillation counter, Neutron detection
  • subatomic particle sensors: Particle detector, scintillator, Wire chamber, cloud chamber, bubble chamber. See Category:Particle_detectors

Non-ionising radiation

  • light sensors, or photodetectors, including semiconductor devices such as photocells, photodiodes, phototransistors, CCDs, and Image sensors; vacuum tube devices carbon monoxide detector minelab metal detector like photo-electric tubes, photomultiplier tubes; and mechanical instruments such as the Nichols radiometer.
  • infra-red sensor, especially used as occupancy sensor for lighting and environmental controls.
  • proximity sensor- safeline metal detectors A type of distance sensor but less sophisticated. Only detects a specific bounty hunter metal detector proximity. May pioneer metal detectors be optical - combination of a photocell and LED or laser. Applications in cell phones, paper detector in industrial metal detectors photocopiers, auto power standby/shutdown mode in notebooks and security metal detectors other devices. May employ a magnet and a Hall effect device.
  • scanning laser- A narrow beam of laser lightning detectors light is scanned over the scene by a mirror. A photocell sensor located at an offset responds when the beam is reflected treasure hunter metal detectors from goring kerr metal detectors an object to the sensor, whence the distance is calculated by triangulation.
  • focus. A large aperture lens may food metal detectors be focused by a servo system. The distance to an in-focus scene element may radar detector tests be determined by the lens setting.
  • binocular. Two images gathered on a known treasure hunter metal detector baseline are brought into coincidence by a system of mirrors and prisms. The treasure hunting metal detector adjustment is used to determine distance. Used in some cameras (called best rated metal detectors range-finder cameras) and on a larger scale in early battleship range-finder
  • interferometry. Interference fringes between handheld metal detectors transmitted and reflected lightwaves produced by a coherent source such as a laser are counted and the distance is calculated. Capable industrial metal detector of extremely high precision.
  • Scintillometers measure atmospheric optical disturbances.

Acoustic

  • sound sensors: pioneer metal detector microphones, hydrophones, seismometers.

acoustic: uses ultrasound time-of-flight echo return. Used loma metal detectors in mid 20th century polaroid cameras and applied also to robotics. Even older systems like Fathometers (and fish finders) and best metal detectors other 'Tactical Active' Sonar garrett detector (Sound Navigation And Ranging) systems in naval applications which mostly use audible gas detector sound frequencies.

Other types

  • motion sensors: radar gun, speedometer, tachometer, odometer, occupancy sensor, turn coordinator
  • orientation sensors: gyroscope, artificial horizon, ring passport radar detector laser gyroscope
  • distance sensor (noncontacting) Several technologies can be applied treasure metal detectors to sense distance: magnetostriction

Non Initialized systems

  • Gray code wireless motion detector strip or wheel- a number of photodetectors can sense a pattern, creating a binary number. build a metal detector The gray code is a mutated pattern that ensures that only one bit of metal detectors australia information changes with each measured step, thus avoiding ambiguities.

Initialized systems

These require starting from treasure detectors a known distance and accumulate incremental changes in measurements.

  • Quadrature wheel- An disk-shaped optical mask is treasure hunting metal detectors driven by a gear train. Two photocells detecting light passing garrett walk through metal detectors through the mask can determine a partial revolution of the mask and the direction of that rotation.
  • whisker sensor- A type gold prospecting metal detectors of touch sensor and proximity sensor.

Classification of kenneth cole metal detector satchel measurement errors

A good sensor obeys the following rules:

  1. the sensor should be leak detector for propane sensitive to the measured property
  2. the sensor should be insensitive to any other property
  3. the sensor should not influence cheap radar detectors the measured property

In the ideal situation, the output first alert smoke detectors signal of a sensor is exactly proportional to the value of the measured property. detectors The gain is then defined as the ratio gas detectors between output signal and measured property. For example, if a sensor measures temperature and has a voltage output, metal detector finds the gain is a constant with the unit [V/K].

If the sensor is not ideal, several types of deviations radar detector detector can be observed:

  • The gain radon detectors may in practice differ from the value specified. This is called a gain error.
  • Since the range of the output water leak detector signal is always limited, the output signal valentine radar detector will eventually clip when the measured property exceeds the limits. The full scale range defines the outmost values metal detectors in nottingham uk of the measured property where motion detector lights the sensor errors are within the specified range.
  • If the output signal is not zero when the measured property is zero, the sensor radiation detector has an offset or bias. This is defined as the output of the sensor at technetics metal detector zero input.
  • If the gain is not constant, best radar detectors this is called nonlinearity. Usually this is defined by the amount the output differs from ideal metal detector circuits behaviour over the full range of the sensor, often noted as smoke detector batteries a percentage of the full range.
  • If the deviation is caused by a rapid change of the measured property over whistler radar detectors time, there is a dynamic error. Often, this behaviour radar detector ratings is described with a bode plot showing gain error and phase shift as function of lightning detector the frequency of a valentine radar detectors periodic input signal.
  • If the output signal slowly changes independent of the measured property, this is defined firex smoke detectors as drift.
  • Long term drift usually indicates a slow degradation of sensor properties underwater metal detectors over a long period of time.
  • Noise is a random deviation of the signal valentine one radar detector that varies in time.
  • Hysteresis is an error caused by the fact that the sensor not instantly follows the change pioneer 101 bounty hunter metal detector of the property being measured, and therefore involves the history of the radar detector comparison measured property.
  • If the sensor has a digital output, the signal is discrete and is essentially 5 gas portable detector an approximation of the measured property. The hidden camera detector approximation error is also called digitization error.
  • If the signal is ir flame detector monitored digitally, limitation of the sampling frequency also causes a dynamic error.
  • The sensor may to some extent be sensitive for other natural gas detector properties than the property being measured. For example, most sensors are influenced by the temperature of their bel radar detector environment.

All these deviations can be classified as systematic cigarette smoke detectors errors or random errors. Systematic errors can sometimes be compensated for detector by means of some kind of calibration strategy. Noise is a random error free spyware detector that can be reduced by signal processing, such as lie detectors filtering, usually at the expense of the dynamic behaviour of the sensor.

Resolution

The resolution of a sensor is metal detector review the smallest change it can voltage detector detect in the quantity that it is measuring. Often in a digital display, the whistler radar detector least significant digit will fluctuate, indicating that changes of that magnitude are only just resolved. The resolution is related to the precision explosive detectors with which the measurement is made. For example, a scanning probe (a microwave detector fine tip near a surface collects an electron tunnelling motorcycle radar detector current) can resolve atoms and molecules.

Biological

All living organisms contain biological sensors nx-490 smoke detector with functions similar to those of the mechanical devices described. Most of these are specialized cells that are smoke detectors detention facilities sensitive to:

  • light, motion, using metal detector on a roof temperature, magnetic fields, gravity, humidity, vibration, pressure, electrical fields, sound, and other physical aspects of white's metal detectors the external environment;
  • physical aspects of the internal environment, such as stretch, motion industrial portable combustible gas detector of the organism, and position of appendages (proprioception);
  • an enormous array of environmental molecules, including toxins, nutrients, and pheromones;
  • many aspects of the nuclear manatee seesaw detector internal metabolic milieu, such as glucose level, oxygen level, or osmolality;
  • an equally varied lie detector test range of internal signal molecules, such as hormones, neurotransmitters, and cytokines;
  • and even the differences between proteins of liquid soap gas leak detectors the organism itself metal detector forum and of the environment or alien creatures.

Artificial sensors that mimic biological sensors by using a biological metal detectors in schools sensitive component, are called biosensors.

The human senses are bel radar detectors examples of specialized neuronal sensors. See Sense.

See also

  • Actuator
  • Data acquisition
  • Data acquisition system
  • Data logger
  • Detection theory
  • Hydrogen microsensor
  • Lateral line
  • Limen
  • List of sensors
  • Machine olfaction
  • Receiver operating characteristic
  • Sensor network

External links

  • Type of sensors and their working
  • Tutorial on interpreting and analyzing cobra radar detector recorded sensor data
  • SensorWiki - Sensor information tailored for music technologists.
  • Federal Standard 1037C, August 7, radar detector test 1996: transducer
  • American National Standard for Telecommunications - Telecom Glossary 2000: radon detector sensor
  • SensEdu; how sensors work
  • "Overview of Sensors and Needs for Environmental Monitoring" Clifford K. Ho, Alex Robinson, David R. Miller and trans bay metal detectors Mary J. Davis Sensors 2005, 5, 4-37 [1] (open access) article
  • The art ad aware 5 7 1 spyware detector of detection: UGS systems make a quantum leap in reliability and utility International Defence Review, 3 August brc smoke detectors home 2006
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