CHOOSING THE RIGHT LEVEL
A level allows you to check that something is positioned at the correct angle. Often this is in either a horizontal of vertical position, but not always.
The mechanism couldn’t be simpler.
A bubble, captured in a liquid, is held inside a clear plastic or acrylic vial. Usually there are alignment marks.
One or more vials is fixed onto, or into, a beam of some kind. The beam rests on the surface to be leveled.
You raise or lower one end of the level until the bubble is centered in the vial, and then you make any needed markings. Job done.
Are all levels are the same? Not quite.
Very small “keyring” levels exist, but these are novelty items that shouldn’t be viewed as truly functional.
The standard DIY level, often called a torpedo level, can be found in tool boxes all over the world. Usually between five and 12 inches long, they’re an excellent multi-purpose tool. A torpedo level might have anywhere from two to four vials, giving you the ability to check horizontal, vertical, 30°, and 45° angles.
Carpenter and construction levels are anywhere from 14 to 48 inches in length. Usually with vials for horizontal and vertical, they occasionally have a 45° vial – or one that can be rotated to your chosen angle.
Post levels have three vials. The level itself is a right-angle construction that wraps around the corner of a square post. It’s self-centering if you have a round post or pipe. This enables you to check for plumb (upright) and level. Some are magnetic, and some have rubber straps to secure them to the post so you can work hands-free.
There are levels specifically designed for bending conduit. Some have a single vial, but most have four. They can be fitted to the conduit with a thumb screw; angles of 0°, 30°, 45°, and 90° can easily be seen as the conduit is bent.
Circular levels, also known as bullseye levels, are round with a single circle, a series of concentric circles, or even cross-hairs. Sometimes called inclinometers, they measure deflection in any direction. Usually they’re permanently fixed to machinery or equipment in situations where maintaining level needs to be regularly monitored.
WHAT ARE LEVELS MADE OF?
Small, cheap levels of six to nine inches in length are often made of plastic. Frequently they have a magnetic strip embedded into one edge. Though the cost is low, accuracy can be poor.
Better levels of six to 12 inches in length are made from aluminum – often cast aluminum – which is still light but also very rigid. It’s not necessarily more durable than plastic, but these levels are better-made and thus more accurate.
Larger levels come in two forms:
As the name suggests, these levels have an I-shaped profile. It’s the same idea as construction girders. You can have considerable length and retain rigidity but not have the weight that a solid beam would have. Aluminum keeps the weight down.