Search results
Results from the WOW.Com Content Network
Also, this liquid solution can be emptied from a small-diameter tube more easily than plain water. In geodesy and surveying, the use of a water level device extended over long distances (sometimes, kilometers) is termed hydrostatic levelling, after the principles of hydrostatic equilibrium and levelling. [2]
In 1914 and 1915, the Forestry Quarterly published a series of articles on the use of the Abney level. [6] [7] [8] These tutorial articles remain useful today, but the primary reference for usage is the 1927 Abney Level Handbook. [3] The Abney level is typically used at the eye height of the surveyor, either hand-held or mounted on a staff at ...
The surveyor does this with the use of a bull's eye level built into the instrument mount. The surveyor looks through the eyepiece of the telescope while an assistant holds a vertical level staff which is graduated in inches or centimeters. The level staff is placed with its foot on the point for which the level measurement is required.
The Abney level is a handheld surveying instrument developed in the 1870s that includes a sighting tube and inclinometer, arranged so that the surveyor may align the sighting tube (and its crosshair) with the reflection of the bubble in the spirit level of the inclinometer when the line of sight is at the angle set on the inclinometer.
The term reduced level is denoted shortly by 'RL'. National survey departments of each country determine RLs of significantly important locations or points. These points are called permanent benchmarks and this survey process is known as Great Trigonometrical Surveying (GTS). The permanent benchmarks act as reference points for determining RLs ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
The level must be horizontal to get a valid measurement. Because of this, if the horizontal crosshair of the instrument is lower than the base of the rod, the surveyor will not be able to sight the rod and get a reading. The rod can usually be raised up to 25 feet high, allowing the level to be set much higher than the base of the rod.
Get a daily dose of cute photos of animals like cats, dogs, and more along with animal related news stories for your daily life from AOL.