Editing Laser level

{{Short description|Control tool for surveying and construction}}
{{Distinguish|Laser line level}}
[[File:Laser-Level.jpg|thumb|250px|A rotary laser level set up and used to level sand fill in trenches. The graduated staff is leaning on the pile of sand.]]
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In [[surveying]] and [[construction]], the '''laser level''' is a control tool consisting of a rotating [[laser]] beam [[projector]] that can be affixed to a [[tripod (surveying)|tripod]]. The tool is leveled according to the accuracy of the device and projects a fixed red or green [[light beam|beam]] in a plane about the horizontal and/or vertical axis.<ref name="Blake2013">{{cite book |first=L. S. |last=Blake |title=Civil Engineer's Reference Book |url=https://books.google.com/books?id=pM_8BAAAQBAJ&pg=SA6-PA14 |publisher=[[Elsevier]] |page=6 |isbn=978-1-4831-0233-7 |date=22 October 2013}}</ref>

==Development==
The concept of a laser level has been around since at least the early 1970s,<ref>{{cite patent|country=US|number=3897637|status=patent}}</ref> the original spinning-mirror design laser plane and line level was patented by the late 1980s,<ref>{{cite patent|country=US|number=4973158|status=patent}}</ref> and the compact lens-based laser line level (as produced by many tool manufacturers today) was patented in the late 1990s. It was invented by Oscar Soliz in the late 1960s, who later sold the rights to it.<ref>{{Cite patent | country = US | number = 5836081 | status = patent | title = Light beam leveling means and method | pubdate = | gdate = 1998-11-17 | fdate = 1996-05-29 | pridate = | inventor = Steven J. Orosz Jr. | invent1 = Orosz, Steven J. Jr. | invent2 = | assign1 = Schroeder, Charles F.}}</ref>

==Rotary laser level==
A rotary laser level is a more advanced laser level in that it spins the beam of light fast enough to give the effect of a complete 360 degree horizontal or vertical plane, thus illuminating not just a fixed line, but a [[horizontal plane]].<ref name="UrenPrice2010">{{cite book|author1=J. Uren|author2=W.F. Price|title=Surveying for Engineers|url=https://books.google.com/books?id=iQEdBQAAQBAJ&pg=PA543|date=17 March 2010|publisher=Palgrave Macmillan|isbn=978-1-137-05279-7|pages=543–}}</ref> The laser beam projector employs a rotating head with a [[mirror]] for sweeping the laser beam about a vertical axis.  If the mirror is not self-leveling, it is provided with visually readable level vials and manually adjustable screws for orienting the projector. A staff carried by the operator is equipped with a movable sensor, which can detect the laser beam and gives a signal when the sensor is in line with the beam (usually an audible beep). The position of the sensor on the [[graduated (measurement)|graduated]] staff, also known as a grade rod, or story pole, allows comparison of elevations between different points on the terrain. Most laser levels are used in the construction industry.

== Tower-mounted laser level ==
A tower-mounted laser level is used in combination with a sensor on a [[wheel tractor-scraper]] in the process of [[land laser leveling]] to bring land (for example, an [[agriculture|agricultural]] field) to near-flatness with a slight grade for [[drainage]].

==See also==
*[[Dumpy level]]
*[[List of laser articles]]
*[[Laser Machine Control]]

==References==
{{Reflist}}

==External links==
* {{ cite patent
 | country = US
 | number = 4062634
 | status = patent
 | title = System for controlling attitude of laser beam plane
 | pubdate = 
 | gdate = 1977-12-13
 | fdate = 1975-02-10
 | pridate = 
 | invent1 = Rando, Joseph F.
 | invent2 = Kahn, Michael E.
 | invent3 = Heumann, Thomas E. 
 | invent4 = Luebbers, Scott S. 
 | assign1 = Spectra-Physics, Inc.
}}
* [https://web.archive.org/web/20190914000230/http://www.dswcpunjab.gov.in/contents/ Resource conservation through laser leveling]

{{Measuring and alignment tools}}
{{Authority control}}

[[Category:Construction equipment]]
[[Category:Construction surveying]]
[[Category:Laser applications]]
[[Category:Surveying instruments]]