spirit levels

[Emanuel Berg]

When and how does decalibration occur?

[Emanuel Berg]

Good rule, easy to remember :)

[-MIKE-]

Doesn't really have to be level. If it hits the line or is the same distance from the line when flipped, it's level.

[Markem]

Banging around, more expensive levels have an adjustment for the bubble, though I have not seen one for sometime for sale.

[krw]

It's quite a useful technique when buying a new level. Home Depot has a lot of them to try (but discourage the throwing part). ;-)

[krw]

True, it's just easier if it's level. Comparing it to another level makes it so you don't even need a fixed place to test (sometimes difficult in a store).

[-MIKE-]

Tell me about it. I like HF but I need to test their levels. I have a 6 footer from there and it's too cheap not to buy, but I had to go through about 7 of them before I found one that was acceptable. Not level, acceptable.

[krw]

The problem with calibrations is that the calibration mechanism, itself, is often the biggest reason calibration is necessary.

[DerbyDad03]

A level itself isn't level...unless it's laying on something level.

[Markem]

Work in a calibration lab once, so that is a good thing to me. ;)

[-MIKE-]

Yeah, I'm pretty sure everyone, you included, knows what I mean.

[krw]

If you use a level to compare against, it doesn't matter that the (test) level is level (see above) or even that it's a good level, it just needs to be somewhat close to being level and, of course, repeatable.

[-MIKE-]

It's not going to help at the store, but I make a habit of having the front of my workbench be perfectly level and perfectly flat on the front edge. It's nice to be able to quickly check a level you dropped and to be able to quickly check an edged board without using a held straightedge against it.

The long, perfectly straight front edge also makes it a quick task to check squares for square using the mark and flip method.

[Clare Snyder]

abuse

[Puckdropper]

DerbyDad03 wrote in news: [e-mail]:

You can rest assured that a level sitting on a level is truly on the level.

Puckdropper

[DerbyDad03]

I guess I should have included the: ;-)

[Just Wondering]

Perhaps. I was responding to the stated example about "the only way to tell" with another way to tell. As someone else pointed out, you could also check with your level oriented in one direction, then turn your level end-for-end and compare the result. There are probably lots of other ways to tell.

[-MIKE-]

Well, there it is, right there. ^^^^ :-p

[Bill]

After about 25 posts, no one has come back to the OP's point that a level can indicate that a surface is level ("both ways") even for a surface which is slightly off-level. Different levels have different tolerances by design. As I indicated in my post, a 100% accurate level would be a PITA. But, I believe that there are different categories of bubble levels. I think this is left to be addressed.

[Emanuel Berg]

100% literally would be impossible but 100% practically speaking - why would that be a PITA? Because nothing would ever satisfy it?

Well, if so, a ruler for example - I always considered that 100% accurate practically speaking but that hasn't stopped anyone from using it as far as I know?