# How accurate would this measurement be?

**URL:** <https://boards.straightdope.com/t/how-accurate-would-this-measurement-be/696032>\
**Category:** Factual Questions\
**Created:** [August 20, 2014, 7:53pm UTC](https://boards.straightdope.com/t/how-accurate-would-this-measurement-be/696032 "2014-08-20T19:53:25Z")\
**Posts on this page:** 2\
**Page:** 2

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**Author:** ![August\_West](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/august_west/32/18069_2.png) [@August\_West](https://boards.straightdope.com/u/August_West)\
**Post date:** [August 21, 2014, 4:23pm UTC](https://boards.straightdope.com/t/how-accurate-would-this-measurement-be/696032/21 "2014-08-21T16:23:17Z")

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I think I’ve got it now. You’re measuring distance in one plane only, perpendicular to the line shot from, so you need a way to walk down the center line and mark all arrows that are parallel to that line.

I’m going to go back to lasers, because _lasers!_ So what if you had a vertical stick with a rotary laser level mounted? You could walk down the center line and the beam would broadcast perpendicular to the line. Here’s [one on amazon](http://www.amazon.com/Johnson-Level-Tool-40-0918-Rotary/dp/B001H1HKAO/ref=pd_cp_hi_0) for $70. You could also get the laser detector for even more accuracy.

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**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\
**Post date:** [August 21, 2014, 4:33pm UTC](https://boards.straightdope.com/t/how-accurate-would-this-measurement-be/696032/22 "2014-08-21T16:33:19Z")

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> [@August\_West](#):
>
> I think I’ve got it now. You’re measuring distance in one plane only, perpendicular to the line shot from, so you need a way to walk down the center line and mark all arrows that are parallel to that line.
> 
> I’m going to go back to lasers, because _lasers!_ So what if you had a vertical stick with a rotary laser level mounted? You could walk down the center line and the beam would broadcast perpendicular to the line. Here’s [one on amazon](http://www.amazon.com/Johnson-Level-Tool-40-0918-Rotary/dp/B001H1HKAO/ref=pd_cp_hi_0) for $70. You could also get the laser detector for even more accuracy.

Thats perfect!! And the price is right at what we need!

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