I am trying to get some idea of the lie of the land around my house to plan some landscaping such as leveling lawns, building retaining walls and sorting out water drainage issues.
I got one of these [url="http://www.toolmart.com.au/lal20xkt.html"]dumpy levels[/url] to have a play with.
Anyone used one? I was hoping someone would be willing/able to answer a few questions....
I've had it out and taken a bunch of readings which, when plotted into Sketchup, are all fairly inaccurate for several reasons.
There is a button underneath that I think is the magnetically dampened compensator, and it does a great job of steadying the image, but I find it impossible to press without altering the position of the level ie. pulling it up or down a little. Am I just clumsy and hamfisted, or amidoingitwrong?
Also, the range finder aspect of it seems pretty loose rounding to the nearest 100mm. I guess a maximum error of 5cm isn't that much? Is that the case and it is usual to use a long tape measure for better accuracy, or is my maths wrong?
How do you align it to north correctly? There is a large magnet inside that screws with a compass and I don't think my mobile phone GPS is accurate enough ....
Any surveyors out there who would care to share their tricks?
Or is it the case that I am asking too much of this instrument and really need a theodolite?
Cheers