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Infrared thermometer

 
Infrared Thermometer

 
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Infrared thermometer
 
 
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Infrared thermometers measure temperature
Temperature

In physics, temperature is a physical property of a Physical system that underlies the common notions of hot and cold; something that feels hotter generally has the greater temperature....
 using blackbody radiation (generally infrared
Infrared

Infrared radiation is electromagnetic radiation whose wavelength is longer than that of visible light , but shorter than that of terahertz radiation and microwaves ....
) emitted from objects. They are sometimes called laser thermometers if a laser
Laser

A laser is a device that emits light through a process called stimulated emission. The term laser is an acronym for light amplification by stimulated emission of radiation....
 is used to help aim the thermometer, or non-contact thermometers to describe the device’s ability to measure temperature from a distance. By knowing the amount of infrared energy emitted by the object and its emissivity
Emissivity

The emissivity of a material is the ratio of energy Radiation by a particular material to energy radiated by a black body at the same temperature....
, the object's temperature can be determined.

The most basic design consists of a lens to focus the infrared energy
Energy

In physics, energy is a scalar physical quantity that describes the amount of Work_ that can be performed by a force. Energy is an attribute of objects and systems that is subject to a conservation law....
 on to a detector, which converts the energy to an electrical signal that can be displayed in units of temperature after being compensated for ambient temperature variation.






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Infrared thermometers measure temperature
Temperature

In physics, temperature is a physical property of a Physical system that underlies the common notions of hot and cold; something that feels hotter generally has the greater temperature....
 using blackbody radiation (generally infrared
Infrared

Infrared radiation is electromagnetic radiation whose wavelength is longer than that of visible light , but shorter than that of terahertz radiation and microwaves ....
) emitted from objects. They are sometimes called laser thermometers if a laser
Laser

A laser is a device that emits light through a process called stimulated emission. The term laser is an acronym for light amplification by stimulated emission of radiation....
 is used to help aim the thermometer, or non-contact thermometers to describe the device’s ability to measure temperature from a distance. By knowing the amount of infrared energy emitted by the object and its emissivity
Emissivity

The emissivity of a material is the ratio of energy Radiation by a particular material to energy radiated by a black body at the same temperature....
, the object's temperature can be determined.

The most basic design consists of a lens to focus the infrared energy
Energy

In physics, energy is a scalar physical quantity that describes the amount of Work_ that can be performed by a force. Energy is an attribute of objects and systems that is subject to a conservation law....
 on to a detector, which converts the energy to an electrical signal that can be displayed in units of temperature after being compensated for ambient temperature variation. This configuration facilitates temperature measurement from a distance
Distance

Distance is a numerical description of how far apart objects are. In physics or everyday discussion, distance may refer to a physical length, a period of time, or an estimation based on other criteria ....
 without contact with the object to be measured. As such, the infrared thermometer is useful for measuring temperature under circumstances where thermocouples or other probe type sensors cannot be used or do not produce accurate data for a variety of reasons.

Some typical circumstances are where the object to be measured is moving; where the object is surrounded by an electromagnetic field
Electromagnetic field

The electromagnetic field is a physical field produced by electric charge. It affects the behavior of charged objects in the vicinity of the field....
, as in induction heating
Induction heating

Induction heating is the process of heating an electrically conducting object by electromagnetic induction, where eddy currents are generated within the metal and resistance leads to Joule heating of the metal....
; where the object is contained in a vacuum
Vacuum

A vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty," but in reality, no volume of space can ever be perfectly empty....
 or other controlled atmosphere; or in applications where a fast response is required.

Infrared thermometers can be used to serve a wide variety of temperature monitoring functions. A few examples provided to this article include:
  • Detecting clouds for remote telescope operation
  • Checking mechanical equipment or electrical circuit breaker boxes or outlets for hot spots
  • Checking heater or oven temperature, for calibration and control purposes
  • Detecting hot spots / performing diagnostics in electrical circuit board manufacturing
  • Checking for hot spots in fire fighting situations
  • Monitoring materials in process of heating and cooling, for research and development or manufacturing quality control situations


There are many varieties of infrared temperature sensing devices available today, including configurations designed for flexible and portable handheld use, as well many designed for mounting in a fixed position to serve a dedicated purpose for long periods.

Specifications of portable handheld sensors available to the home user will include ratings of temperature accuracy (usually plus or minus a degree or two) and other parameters. The distance-to-spot ratio (D:S) is the ratio of the distance to the object and the diameter of the temperature measurement area. For instance if the D:S ratio is 12:1, measurement of an object 12 inches away will average the temperature over a 1-inch diameter area. The sensor may have an adjustable emissivity setting, which can be set to measure the temperature of reflective (shiny) and non-reflective surfaces. A non-adjustable thermometer can be used to measure the temperature of a shiny surface by applying a non-shiny paint or tape to the surface.

The most usual infrared thermometers are the:

  • Spot Infrared Thermometer or Infrared Pyrometer
    Pyrometer

    Pyrometer is any non-contacting device that intercepts and measures thermal radiation. This measure is used to determine temperature, often of the object's surface....
    , which measures the temperature at a spot on a surface (actually a relatively small area determined by the D:S ratio).


Related equipment, although not strictly thermometers, are:

  • Infrared Line Scanning Systems scan a larger area, typically by using what is essentially a spot thermometer pointed at a rotating mirror. These devices are widely used in manufacturing involving conveyors or "web" processes, such as large sheets of glass or metal exiting an oven, fabric and paper, or continuous piles of material along a conveyor belt.


  • Infrared Cameras
    Thermographic camera

    A thermographic camera, sometimes called a FLIR , or an infrared camera less specifically, is a device that forms an image using infrared radiation, similar to a common camera that forms an image using optical spectrum light....
     are essentially infrared thermometers which measure the temperature at many points over a relatively large area to generate a two-dimensional image, with each pixel representing a temperature. This technology is more processor- and software-intensive than spot or scanning thermometers, and is used for monitoring large areas. Typical applications include perimeter monitoring used by military or security personnel, inspection / process quality monitoring of manufacturing processes, and equipment or enclosed space hot or cold spot monitoring for safety and efficiency maintenance purposes. A photographic camera
    Camera

    A camera is a device that records images, either as a still photograph or as moving images known as videos or movies. The term comes from the camera obscura , an early mechanism of projecting images where an entire room functioned as a real-time imaging system; the modern camera evolved from the camera obscura....
     using infrared
    Infrared

    Infrared radiation is electromagnetic radiation whose wavelength is longer than that of visible light , but shorter than that of terahertz radiation and microwaves ....
     film
    Film

    Film encompasses individual motion pictures, the field of film as an art form, and the film industry. Films are produced by recording images from the world with cameras, or by creating images using animation techniques or special effects....
     and suitable lens, etc., is also called an infrared camera.


Gallery


External links



See also

  • Infrared camera
  • Thermography
    Thermography

    Infrared Thermography, thermal imaging, thermographic imaging, or thermal video, is a type of infrared imaging science. Thermographic cameras detect electromagnetic radiation in the infrared range of the electromagnetic spectrum and produce images of that radiation....