Just wondering over what sort of distance one of the diy laser levels
will work? I need to check a level over a couple of hundred feet and
suspect that it wouldn't be powerful enough but assume that I could do
it in stages by laying out some sort of peg system.

Kevin

Kev wrote:
Just wondering over what sort of distance one of the diy laser levels
will work? I need to check a level over a couple of hundred feet and
suspect that it wouldn't be powerful enough but assume that I could do
it in stages by laying out some sort of peg system.

Mine will send the little red dot a hundred feet easily if used after dusk.
Don't know how accurate it would be though.

Dave

Just wondering over what sort of distance one of the diy laser levels
will work? I need to check a level over a couple of hundred feet and
suspect that it wouldn't be powerful enough but assume that I could do
it in stages by laying out some sort of peg system.

Kevin

Is the distance too great to consider a U-Tube that is made of
normal Wine making type poly tube. I've used this method from inside
to the outside of a house with the tube going out of a window. As long
as you keep any rises below the two ends you wont have a problem. You
can also colour the water with red or blue ink. Remember, both ends
must be open to atmosphere when in use.

Chris.

On 10 Jan 2006 02:07:39 -0800, Kev wrote:

Just wondering over what sort of distance one of the diy laser
levels will work? I need to check a level over a couple of hundred
feet and suspect that it wouldn't be powerful enough

How accurate do you want the level over that distance? The cheap ones
quote something like 1mm/m. 200' = 61m you could be 61mm out...

You'll probably have fun in day light but in poor light or at night
with a bit white card to follow the spot and someone to (carefully)
adjust the level as you move away to the far end it shouldn't be a
problem.

--
Cheers
Dave. pam is missing e-mail

wrote:
Just wondering over what sort of distance one of the diy laser levels
will work? I need to check a level over a couple of hundred feet and
suspect that it wouldn't be powerful enough but assume that I could do
it in stages by laying out some sort of peg system.

Kevin

Is the distance too great to consider a U-Tube that is made of
normal Wine making type poly tube. I've used this method from inside
to the outside of a house with the tube going out of a window. As long
as you keep any rises below the two ends you wont have a problem. You
can also colour the water with red or blue ink. Remember, both ends
must be open to atmosphere when in use.

Chris.

That method was going to be my fall back but it looks as though the
laser level might do it.

Kevin

david lang wrote:
Kev wrote:
Just wondering over what sort of distance one of the diy laser levels
will work? I need to check a level over a couple of hundred feet and
suspect that it wouldn't be powerful enough but assume that I could do
it in stages by laying out some sort of peg system.

Mine will send the little red dot a hundred feet easily if used after dusk.
Don't know how accurate it would be though.

Dave

It doesn't have to be hugely accurate so it might do the job.

Kevin

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Dave Liquorice wrote:
Kev wrote:
Just wondering over what sort of distance one of the diy laser
levels will work? I need to check a level over a couple of hundred
feet and suspect that it wouldn't be powerful enough

How accurate do you want the level over that distance? The cheap ones
quote something like 1mm/m. 200' = 61m you could be 61mm out...

There are other factors involved over and above levelling.


You'll probably have fun in day light but in poor light or at night
with a bit white card to follow the spot and someone to (carefully)
adjust the level as you move away to the far end it shouldn't be a
problem.

I expect the result will be very poor. You'd be much better
off with a dumpy level.

Quite right, the light beam will sag over that sort of distance....

On Tue, 10 Jan 2006 03:11:02 -0800, Kev wrote:


wrote:
Just wondering over what sort of distance one of the diy laser levels
will work? I need to check a level over a couple of hundred feet and
suspect that it wouldn't be powerful enough but assume that I could do
it in stages by laying out some sort of peg system.

Kevin

Is the distance too great to consider a U-Tube that is made of
normal Wine making type poly tube. I've used this method from inside
to the outside of a house with the tube going out of a window. As long
as you keep any rises below the two ends you wont have a problem. You
can also colour the water with red or blue ink. Remember, both ends
must be open to atmosphere when in use.

Chris.

That method was going to be my fall back but it looks as though the
laser level might do it.

Kevin

If you use the tube method, I recommend getting some with a bigger bore,
about 1cm or a bit bigger. I tried this with 5mm bore tub and it's a
sod getting the air bubbles out.

Although it's not massively accurate (depends how closely to can sight the
meniscus onto what you are marking) it has the advantage it works without
much degradation over moderate distances.

Cheers

Tim

Phil wrote:
Quite right, the light beam will sag over that sort of distance....

Phil - WTF are you on about? Please learn to quote correctly.

Kev wrote:

david lang wrote:
Kev wrote:
Just wondering over what sort of distance one of the diy laser levels
will work? I need to check a level over a couple of hundred feet and
suspect that it wouldn't be powerful enough but assume that I could do
it in stages by laying out some sort of peg system.

Mine will send the little red dot a hundred feet easily if used after dusk.
Don't know how accurate it would be though.

It doesn't have to be hugely accurate so it might do the job.

It won't send a little red dot a hundred feet.
The cheaper units typically have a divergance of around half a
milliradian. For less divergance, you need to be able to focus onto an
objective, and have a bigger lens.
The cheaper ones will do a spot of maybe 5cm at 100m, and this is
trivial to see at dusk.

Ian Stirling wrote:

It won't send a little red dot a hundred feet.
The cheaper units typically have a divergance of around half a
milliradian. For less divergance, you need to be able to focus onto an
objective, and have a bigger lens.
The cheaper ones will do a spot of maybe 5cm at 100m, and this is
trivial to see at dusk.

Mine will shine a red dot onto the chimney of a house at the end of the cul
de sac, well over 100 ft away. Granted I don't know how big the dot is, but
it certainly reaches that distance.

Dave

david lang wrote:
Ian Stirling wrote:

It won't send a little red dot a hundred feet.
The cheaper units typically have a divergance of around half a
milliradian. For less divergance, you need to be able to focus onto an
objective, and have a bigger lens.
The cheaper ones will do a spot of maybe 5cm at 100m, and this is
trivial to see at dusk.

Mine will shine a red dot onto the chimney of a house at the end of the cul
de sac, well over 100 ft away. Granted I don't know how big the dot is, but
it certainly reaches that distance.

True - but the dot it sends is not little.
At 100 feet, you're looking at 2-3cm or so.

If you're next to the dot at night, you can probably see it perfectly
well until the dot gets to well over a meter.

And then - looking towards the laser, it's visible when the spot is many
tens of meters wide.

On 10 Jan 2006 02:07:39 -0800, "Kev" wrote:

Just wondering over what sort of distance one of the diy laser levels
will work?

Miles and miles if you can work after dark. The spot is small enough,
it's just seeing it.

Otherwise it's still easier to use a telescope to look at a mark in
daylight.

Ian Stirling wrote:
david lang wrote:
Ian Stirling wrote:

It won't send a little red dot a hundred feet.
The cheaper units typically have a divergance of around half a
milliradian. For less divergance, you need to be able to focus onto an
objective, and have a bigger lens.
The cheaper ones will do a spot of maybe 5cm at 100m, and this is
trivial to see at dusk.

Mine will shine a red dot onto the chimney of a house at the end of the cul
de sac, well over 100 ft away. Granted I don't know how big the dot is, but
it certainly reaches that distance.

True - but the dot it sends is not little.
At 100 feet, you're looking at 2-3cm or so.

If you're next to the dot at night, you can probably see it perfectly
well until the dot gets to well over a meter.

And then - looking towards the laser, it's visible when the spot is many
tens of meters wide.

I should have mentioned - that I've also used a laser pointer, a bit of
15mm pipe insulation to grab it, and a bit of waste pipe, to slip a
laser pointer into accurate alignment with a pair of binoculars.
The binoculars then form a beam expander, and greatly reduce the
divergance.