Angle Measurement Error

General Basic field operations performed by a surveyor involve linear and angular measurements. Through application of mathematics (geometry and trigonometry) and angle measurement calculator spatial information knowledge,the surveyor converts these measurements to the horizontal and

Angle Measurement Worksheet

vertical relationships necessary to produce maps, plans of engineering projects, or Geographical Information System/ Land Information System

Angle Measurement Problems

(GIS/LIS). The highway surveyor must be adept at making the required measurements to the degree of accuracy required. Various types of engineering works require various tolerances in the precision

Angle Measurement Formula

of the measurements made and the accuracies achieved by these measurements. The use of common sense and development of good surveying practice in all phases of a survey cannot be overemphasized. All conditions that may be encountered in the "real world" during the actual field survey cannot be covered in any manual. A manual may specify certain techniques, angle measurement of polygons such as a certain number of repeated operations, to achieve a required accuracy. The surveyor must then often use judgment based on the equipment being used and the field conditions encountered, to modify those techniques. Some field conditions (heat waves or wind for example) may make it impossible to perform some operations to a consistent degree of accuracy. 3.2 Accuracy and Precision 3.2.1 Accuracy Accuracy is the degree of conformity with a standard or accepted value. Accuracy relates to the quality of the result. It is distinguished from precision that relates to the quality of the operation used to obtain the result. The standard used to determine accuracy can be: An exact known value, such as the sum of the three interior angles of a plane triangle is 180°. A value of a conventional unit as defined by a physical representation thereof, such as the international meter. A survey or map value determined by superior methods and deemed sufficiently near the ideal or true value to be held constant for the

is 1 meter away at 45 degrees, an angle measurement game angular error of 1 degree corresponds to a positional angle measurement online error of over 1.745cm, equivalent to a distance-measurement error of 1.745%. In machine angle measurement sensor design, some components are particularly sensitive to angular errors. For example, if the shaft of a lathe is angled slightly, the part http://www.state.nj.us/transportation/eng/documents/survey/Chapter3.shtm will have errors in diameter far down the part. Abbe error can be detrimental to dead reckoning. Formula: ϵ = h sin ⁡ θ {\displaystyle \epsilon =h\sin \theta } ϵ {\displaystyle \epsilon } the error. h {\displaystyle h} the distance. θ {\displaystyle \theta } https://en.wikipedia.org/wiki/Abbe_error the angle. References[edit] External links[edit] Retrieved from "https://en.wikipedia.org/w/index.php?title=Abbe_error&oldid=727556526" Categories: ErrorTrigonometry Navigation menu Personal tools Not logged inTalkContributionsCreate accountLog in Namespaces Article Talk Variants Views Read Edit View history More Search Navigation Main pageContentsFeatured contentCurrent eventsRandom articleDonate to WikipediaWikipedia store Interaction HelpAbout WikipediaCommunity portalRecent changesContact page Tools What links hereRelated changesUpload fileSpecial pagesPermanent linkPage informationWikidata itemCite this page Print/export Create a bookDownload as PDFPrintable version Languages ItalianoPolskiУкраїнська Edit links This page was last modified on 29 June 2016, at 19:22. Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. Privacy policy About Wikipedia Disclaimers Contact Wikipedia Developers Cookie statement Mobile view

3) The flatness of the surfaces being viewed by the autocollimators. This factor is a large contributor to measurement error and uncertainty. NOTE: The type of autocollimator http://starrett-webber.com/AG31.html used in the measurement will have a great influence on the resulting measurement. Different kinds of autocollimators may give different results. How this is possible will be shown below. If the surface in not ideally flat, the angle of reflection may be different than the angle of incidence. The autocollimators used by Webber Gage have a 2-inch diameter beam and are manually read. The return image angle measurement in visually centered between two target lines. The reading is taken off a micrometer dial. For reference and Calibration Grade blocks, the beam nearly covers the whole area of the block. The angle indicated by the autocollimator is the average returned over the entire surface of the angle block. Autocollimators which have narrower beams such a laser autocollimators may give different readings than autocollimators that angle measurement error cover the entire surface. The average reflected image in this picture is different than the average reflected image of the picture above. Positioning of the autocollimator may also effect the readings of an angle block. This is another effect due to flatness of the block. If the beam of the autocollimator is not centered on the angle block, different readings may result. The measurement uncertainty factor (k=2) due to flatness is estimated to be given by: U = WF / (4.85 B) where U is expressed in arc seconds and W = maximum dimension of the angle block (Width or Length) in inches, or equal to B if W is smaller than B F = measured flatness of the angle gage block surface in microinches B = Beam diameter of the autocollimator in inches. Note: 1 arc second is approximately 4.85 microinches of taper per inch. 4) Pyramidal Error. The pyramidal angle is the deviation from 90°, forward or backwards, that the face of the angle block has to the beam of the autocollimator. Ideally, the face of angle block is perpendicular to the vector represented by the centerline of the beam of the autoc

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