What is a Level?

What is a Dumpy or Automatic LevelA laser level is a fairly recent invention, and has
Let us look at the history of surveying levels.changed the way surveying is being done. With a
Since the Dumpy level was invented in earlyself leveling laser level you can be assured that
1700's it has been considered the standard, thatyour measurement will be as accurate as humanly
was up until around the 1830's when the transitpossible. A laser level is a level that uses a laser
level was invented. Recently the level has changedlight to project a line. Most surveying laser levels
faster than you can keep up with it, but throughus a rotating mirror so that they can project a
all this the Dumpy level has remained a reliablehorizontal plane around in a circle. A laser level is
back up just in case the modern levelsmore accurate then a Dumpy level but can break
breakdown.down from time to time.
A dumpy level, builder's auto level, levelingAs its name suggests, a laser level is a leveler
instrument or automatic level is an opticalthat illuminates a horizontal plane using a laser. It
instrument used in surveying and building towas originally developed by an inventor named
transfer, measure, or set horizontal levels.Steve Orosz. The laser level works by being
The level instrument is set up on a tripod and,stationed on a tripod. This projector also has a
depending on the type, either roughly orrotatable head with a mirror, so that the laser
accurately set to a leveled condition usingbeam can also sweep across the vertical axis. It is
footscrews (levelling screws). The operator looksadjusted through the many visually interpretable
through the eyepiece of the telescope while anlevel vials and the numerous screws that must be
assistant holds a tape measure or graduated staffmanually adjusted by a human for correction
vertical at the point under measurement. Theprojection.
instrument and staff are used to gather and/orThen, a staff with an operator equipped to it with
transfer elevations (levels) during site surveys ora moveable sensor, detects the laser beam and
building construction. Measurement generally startsmakes an audible signal every time the line is in
from a benchmark with known height determinedaccordance with the beam. The key behind the
by a previous survey, or an arbitrary point withlaser level is the position of the sensor on the
an assumed height.graduated staff, as it interprets the elevation
The Dumpy level was a simple device that wasdifferences between various points on a certain
nothing more then a small telescope with a bubbleterrain.
level attached to it. The newer Dumpy levelsThere is also a tower mounted laser level. This is
have a few more bell and whistles but are still theoften used together with the wheel
same basic design. Some of the drawbacks of atractor-scraper, which has a sensor attached to it.
Dumpy level are the time it takes to set up andThis is commonly used during land laser leveling
get level, the slightest mistake in setting it up canprocess (such as agricultural lands and when
result in an inaccurate reading, and taking morebuilding the foundations of skyscrapers) to flatten
then one measurement from different directionsthe land at a certain degree for a functional
can be off if not set up perfectly.drainage system.
A Laser Level And How It Works