What is this device called and what is it's purpose?

[u587162]

I originally thought it's to calculate degrees, but now understand it might be used to find levels?

I'm curious to know how does it works, I guess it uses lasers?

 

[Burnerman]

Its a theodolite, used for measuring horizontal and vertical angles.....used for getting levels on building sites.
We used to call our original one the 'spyglass'
John

 

[bernardgreen]

Could do both. Levels and angles. Basically it is used to measure differences in hieghts between places. Theodolite and yes it probable does use a laser but not all do. Some use a target on a pole and the cahp in orange has to line up his instrument onto the target

EDIT too slow burner man beat me

 

[u587162]

How accurate are the measurements, are we talking millimetres out or a few cms?

 

[Burnerman]

The thing I was brought up on was simply a telescope, through which you looked at a telescopic pole with measurements on - the image was upside down so the numbers on the pole were inverted.
It was very accurate - you had to bray a levelling peg into the ground at various intervals until the levelling pegs were all the same height. These gave you the layout for a perfectly level concrete raft, for example. We used to call this 'settin' the site oot'.
No doubt more modern theodolites use lasers - these may well be better over distances, I don't know - but the principle is exactly the same.
I just cant remember the name of that pole.....wooden telescopic in 3 stages, white background, red numbers....when you collapsed it, it obligingly sliced the skin off between thumb and fore finger
John

 

[theprinceofdarkness]

Cheapo lasers are +-3mm/m. . . . proper surveying instruments are 1 part in 10,000. A colleague of mine measures the " out of plumb" of 1000 ft masts, he can read it down to inches.
Frank

 

[^woody^]

Its a theodolite

It's actually a Total Station, which measures distance, angles and changes in level and processes the information electronically.

It's optical and does not use lasers

 

[bernardgreen]

which measures distance

It's optical and does not use lasers

How does it measure distance ? Surely not by auto-focusing on the distant target

 

[^woody^]

It uses prisms and mirrors to shape an infra red wave, which needs to be reflected off a target mirror.

 

[bernardgreen]

So maybe an infra red laser ?

 

[^woody^]

No. No laser, it's an optical instrument or electro-optical

 

[footprints]

Na! All wrong! It's a "What the Builder saw" machine!

 

[SimonH2]

I just cant remember the name of that pole.....

Staff

 

[chrisjackson184]

It's a Total Station, as others have said it uses infrared to measure distances and sensors within the unit to measure horizontal and vertical angles, from these distances and angles levels and coordinates can be calculated as long as you have known points to start with. The calculations are basic trigonometry and most devices do these internally and just give you the answer, although they can provide raw data also. Accuracy is dependent on the skill and thoroughness of the user. The individual measurements can be very precise, but to get a point set out to around +/- 2mm is a normal sort of tolerance that is practically achievable, some people will claim better but in my experience it is rare to regularly achieve it.

 

[joe-90]

I used to get petrol at a Total Station.