Laser levels How to?

Page 2 of 2  
The important thing to remember is that the laser gives you a level datum, form which you can measure up or down.
dg

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

It actually gives you a line, which may (or more usually) may not be level. A few weeks ago I was measuring across a large room using the high tech measure (hose pipe with bits of clear tube stuck in either end and filled with water) when a "consultant" came in (his card said "BA (design for buildins)" (sic) Luton" - which I think is the modern day version of "BSc (Calcutta) (failed)" for those that remember the proper version of "1066 and all that" before it was sanitised)).
He wore a shiny grey suit and white socks with black plastic shoes.
Producing his laser level and balancing it on a remarkably shoddy tripod he proceeded to mark off "levels" which were a good 5" out from my water level.
When questioned he questioned whether or not my hosepipe had a calibration certificate and if not how did I know it was accurate. When asked if he knew about gravity he wanted to know if they were Investors in People certified (which his organisation apparently was) and if not his levels were more level than gravities, no matter who they were, because his were certified.
For his next trick he has to make water flow uphill, but I haven't mentioned that to him yet.
--
Peter Parry.
http://www.wpp.ltd.uk/
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Suited idiot aside, I've had a hose level be off... I'd checked it against itself, and it was off by half an inch. Turned out I'd missed a bubble in the non-transparent bit.
If I had to use one frequently and wanted a "permanent" one rather than putting one together from bits when I wanted one, I'd use clear tubing throughout. (Then algae would probably grow in it...)
Thomas Prufer
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Hello Thomas

If you had a permanent one, then couldn't you add a de-algae-fyer to the water, along with some colouring?
--
Simon Avery, Dartmoor, UK
uk.d-i-y FAQ: http://www.diyfaq.org.uk /
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 17 Dec 2003 14:39:10 GMT, snipped-for-privacy@digdilem.org (Simon Avery) wrote:

You'd have to. Table salt, maybe?
I'd leave out the colouring -- that water will drip somewhere sometime...
Thomas Prufer
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 15 Dec 2003 07:55:58 +0100, Thomas Prufer

The real problem with water levels is 'stiction'. I made a level using 1/4" bore clear plastic tube which I had lying around, and found it virtually useless as I could get the water to settle anywhere in about a +/- 30mm band. This seems to be due to the stiction of the water to the inner surface of the tube.
Peter should have somewhat better luck with a wider bore, such as a hose pipe, but it will have some residual uncertainty. I would be interested to know if there are any tables (or calcs) that relate length and bore to uncertainty. Well, obviously there are - what I mean is where are they.
-- Phil Addison The uk.d-i-y FAQ is at http://www.diyfaq.org.uk / Remove NOSPAM from address to reply
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 02 Jan 2004 18:52:40 GMT, Phil Addison wrote:

Drop of washing up liquid added to the water would probably cure that by destroying (or at least much reducing) the surface tension. Untested mind but that is what I would try but agree 1/4" tube does seem a bit narrow to be particulary successfull.
--
Cheers snipped-for-privacy@howhill.com
Dave. pam is missing e-mail
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 02 Jan 2004 18:52:40 GMT, "Phil Addison"
snip

When I tried it I used a 1/2" hose pipe but still got inaccuracy. Mind you it was a full lebgth hose and I gave no thought to bubbles etc.
Paul Mc Cann
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Would the addition of some 'un-stiction' to the tubing change things? I am thinking of a touch of washing up liquid here.
Dave
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 14 Dec 2003 16:40:22 +0000, Paul Mc Cann
Many thanks for all the suggestions.
As I rather suspected its back to paper and string.
Using a stick or staff to transfer the datum to a point higher up is a possible error inducing step.
Having then to join two such transferred marks allows more errors to creep in.
Methinks I'll stick with a 1200mm spirit level,string level or water in transparent hose. ( As someone said, they once had an error in using a water level device. I had a similiar problem which I didn't spot in time. I assumed I made an error in setting the two level markss but I suspect his suggestion that a bubble was trapped in the pipe was the most likely. I'll be more confident trying that method the next time. I suppose a little food coloring in the water would allow any potential bubble trouble makers be spotted .
Paul Mc Cann
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
All levelling operations can induce errors. You are more likely to introduce a considerable error in setting up the level, than you ever would by transferring a mark with a staff
For the majority of domestic or other non structural purposes, these normal errors can be ignored
dg
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I can't agree. The possibility of not getting the staff vertical ( which probably necessitates using a plumb line) is the first opportunity for errors to creep in . And this has to be repeated for each positioning mark
Then one is left trying to transfer a mark up to and beyond arms reach. Step ladders may have to be used.
The staff may have to be affixed to the wall with accuracy.
Two sightings would have to be made for every mark
Sod law will dictate that there will be many times when the use of the staff would be obstructed by existing fittings.
All in all, I think if the laser level could be made do the job, I'm going to get a damn sight more accuracy with that than faffing about with sticks.
I'm well able to set up a level having used dumpy levels many years ago. Anyway its only a matter of centreing a bubble, not exactly rocket science.

ourselves to domestic or even non structural purposes.
The reason I was toying with getting a laser level is the regular requirement we have to fix runs of storage cupboards at varying heights. The runs can be up to 60 feet long and include circumnavigating alcoves etc.
snip
Paul Mc Cann
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 15 Dec 2003 19:13:48 +0000, Paul Mc Cann

I was using non-transparent hosepipe, with bits of clear tube bodged on the ends. If I needed such a level more often, I'd use some clear tubing. Maybe even add valves at the end so it can be left filled, and then also moved without emptying...
Thomas Prufer
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.