{{Short description, Instruments that accurately measure large objects

Laser-de-poursuite-FARO-laser-tracker-vantage2

Laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The firs ...

trackers are instruments that accurately measure large objects by determining the positions of

optical Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultrav ...

targets held against those objects. The

accuracy Accuracy and precision are two measures of '' observational error''. ''Accuracy'' is how close a given set of measurements (observations or readings) are to their '' true value'', while ''precision'' is how close the measurements are to each ot ...

of laser trackers is of the order of 0.025 mm over a distance of several

metres The metre ( British spelling) or meter ( American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its pr ...

. Some examples of laser tracker applications are to align

aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. ...

wings during assembly and to align large machine tools. To take measurements the

technician A technician is a worker in a field of technology Technology is the application of knowledge to reach practical goals in a specifiable and reproducible way. The word ''technology'' may also mean the product of such an endeavor. The use ...

first sets up a laser tracker on a tripod with an unobstructed view of the object to be measured. The technician removes a target from the base of the laser tracker and carries it to the object to be measured, moving smoothly to allow the laser tracker to follow the movement of the target. The technician places the target against the object and triggers measurements to be taken at selected points, sometimes by a

remote control In electronics, a remote control (also known as a remote or clicker) is an electronic device used to operate another device from a distance, usually wirelessly. In consumer electronics, a remote control can be used to operate devices such as ...

device. Measurements can be imported into different types of

software Software is a set of computer programs and associated software documentation, documentation and data (computing), data. This is in contrast to Computer hardware, hardware, from which the system is built and which actually performs the work. ...

plot Plot or Plotting may refer to: Art, media and entertainment * Plot (narrative), the story of a piece of fiction Music * ''The Plot'' (album), a 1976 album by jazz trumpeter Enrico Rava * The Plot (band), a band formed in 2003 Other * ''Plot ...

the points or to calculate deviation from the correct position. The targets are known as "

retroreflective A retroreflector (sometimes called a retroflector or cataphote) is a device or surface that reflects radiation (usually light) back to its source with minimum scattering. This works at a wide range of angle of incidence, unlike a planar mirror, ...

" because they reflect the laser beam back in the same direction it came from (in this case, back to the laser tracker). One type of target in common use is called a spherically mounted retroreflector (SMR), which resembles a ball bearing with

mirror A mirror or looking glass is an object that Reflection (physics), reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the ...

ed surfaces cut into it.

History

The first laser tracker was invented in 1987 by Dr. Kam Lau, CEO of API (Automated Precision, Inc.) while at NIST"NIST", 2010 and made commercially available b
API Metrology
in 1988 with its first production unit being made available to Boeing under a 9-month lease agreement. Tennessee Technology University received an API 6-D laser tracker in 1989. Instruments were later produced by Kern in 1991 following a technology agreement with API. Currently, there are three well known manufacturers of Laser Trackers; FARO, API, and Leica.

Footnotes

References and sources

*Bob Bridges. �

” ''Quality Digest'', June 25, 2009. *James R. Koelsch, �
Should Laser Trackers be in your Arsenal of Metrological Tools?
�� ''Quality Magazine'', March 2012. *“Portable laser tracker measures large volumes accurately.” ''Machine Design'', August 25, 2011, Vol. 83 Issue 14, p19. *Joel Martin. �
Laser tracking fundamentals
” ''Quality Magazine'', May 2007. *Javier Vera. �

” ''Quality Digest''. January 27, 2011. *National Institute of Standards and Technology.

" "NIST Public Affairs Office", June 04, 2010. 3D imaging, Scanner Laser image acquisition Metrology Surveying instruments