Welcome to the Thursday Toolkit series, about tools for building Physical Computing projects.
Ehm, well, not quite :) … here’s how people defined and measured distances some 35 centuries ago:
It’s a stone, roughly 1 meter long, which can be found in the Istanbul Archaeology Museum. In more detail:
Not terribly convenient. I prefer something like this – have had one of them around here at JeeLabs for ages:
Then again, both of these measuring devices are quite a long shot (heh) from today’s laser rangefinders:
For about €82 at Conrad – no, I don’t have stock options, they are privately owned :) – you get these specs:
That’s 2 mm accuracy from 0.5 to 50 meters, i.e. one part in 25,000 (0.004%). Pretty amazing technology, considering that it’s based on measuring the time it takes a brief pulse to travel with (almost) the speed of light!
But you’ll need a 9V battery to make this thing work – everything needs electricity in today’s “modern” world.
No!, it is not about “measuring the time it takes a brief pulse to travel with (almost) the speed of light”. This type of laser distance meters measures the phase difference between original laser pulse and reflected one. Resolution of 1mm gives you approximately ((3*10^8m/s)/2)/0.001m = 6.67 GHz of bandwidth. There is no way capture the light of so low intensity at this speed (almost). Look http://www.repairfaq.org/sam/laserlia.htm for info.
Ah, ok, I must admit I know nothing about how this thing works… thanks for the link!