The Purpose of Surveying. In the general sense, to survey something is to carefully review that object or person and accurately record the results. Nearly every time you make a purchase, you are asked to complete a survey.
The principle of chain surveying is triangulation. This means that the area to survey is spilled into a number of small triangles which should be well-conditioned. In chain surveying, the side of the triangles are measured directly from the field by chain or tape, and no angular measurements are used.
Principles of Surveying. Surveying is the process of finding the relative position of various points on the surface of the earth by measuring distance among them and setting up a map to any reasonable scale. Various methods of surveying are established on very simple fundamental principles.
a distance-measuring device consisting of a chain of 100 links of equal length, having a total length either of 66 feet (20 meters) (Gunter's chain or surveyor's chain) or of 100 feet (30 meters) (engineer's chain). a unit of length equal to either of these.
Errors in Chaining: - The errors that occur in chaining are classified as (i) Compensating, (ii) Cumulative. These errors may be due to natural causes such as say variation in temperature, defects in construction and adjustment of the instrument, personal defects in vision etc.
Basic Principles of Surveying
- BASIC PRINCIPLES IN SURVEYING.
- PRINCIPLE OF WORKING FROM WHOLE TO PART.
- IMPORTANCE OF SCIENTIFIC HONESTY.
- CHECK ON MEASUREMENTS.
- ACCURACY AND PRECISION.
- Horizontal Distance Measurement.
Instruments used for chain surveying
- Chain: Chains are used to measure horizontal distances.
- Arrows: Arrows or making pins are made of tempered steel wire 4mm in diameter and generally 10 arrows are supplied with a chain.
- Pegs:
- Ranging Rods.
- Offset.
- Plumb Bob.
- Cross staff.
The core disciplines of surveying are:
- Land surveying (also known as Cadastral Surveying)
- Engineering surveying.
- Mining surveying.
- Hydrographic (Bathymetric) surveying.
- Geodetic surveying.
- Aerial (Photogrammetry and remote sensing)
- Topographic (Detail/Tachymetry)
- Notes.
A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A chain may consist of two or more links.
To help you make your choice, we have listed the most common types of necklace chains that you need to know about.
- Anchor/Mariner Chain.
- Ball / Bead Chain.
- Box Chain.
- Cable Chain.
- Curb Chain.
- Figaro Chain.
- Rope Chain.
- Singapore Chain.
Levelling in surveying. Levelling is a process of determining the height of one level relative to another. It is used in surveying to establish the elevation of a point relative to a datum, or to establish a point at a given elevation relative to a datum.
History and usage. The chain was originally called an "acre's breadth" because it was the width of a acre, while a furlong was the length. Edmund Gunter, a clergyman mathematician, invented a measuring device called a chain. It was the forerunner of the slide rule.
Because the chains were hand-made, their measurements were rarely exact. Although the Gunter's Chain was the primary tool of surveyors to measure distance in North America from the 1600s to the end of the 1800s, it was eventally replaced by a more sophisticated and accurate instrument, the surveyor's tape.
A well conditioned triangle is a triangle in which no angle is less than 30 degrees. One of the way to survey the area is to divide the entire area is smaller triangles and then take the measurement of sides of the triangles.
An offset can usually refer to 2 things in surveying. The first means a line that is parallel to another significant line - either a boundary line or the centerline of a road. The first means a line that is parallel to another significant line - either a boundary line or the centerline of a road.
Revenue Chain
The number of links are 16, each link being 2 ft.The principle of chain surveying is to divide the area to be surveyed into a network of connected triangles as a triangle is the only simple figure that can be plotted from the lengths of its sides measured in the field.
Based on the observation points and instrument positions direct leveling is divided into different types as follows:
- Simple leveling.
- Differential leveling.
- Fly leveling.
- Profile leveling.
- Precise leveling.
- Reciprocal leveling.
Chain Surveying | Definition, Details, Procedure. Chain survey is the simplest method of surveying. In chain survey, only measurements are taken in the field, and the rest work, such as plotting calculation etc. are done in the office. Here only linear measurements are made i.e. no angular measurements are made.
Open Cross Staff: The common type of cross staff consists of 4 metal arms with vertical slits for sighting through. The head is fixed to the top of an iron stand about 1 . 2 to 1.5 m long this is driven in to the ground. For setting perpendiculars lines, one pair of opposite arms is aligned with the chain line.
The cross-staff was a navigational tool used to measure the angle between the horizon and a celestial body such as the sun or stars. By knowing this angle, a navigator could then determine his latitude and direction. The cross-staff is also referred to as the fore-staff and the Jacob's staff.
An Auto Level is a Professional Leveling Tool used by Contractors, Builders, Land Surveying Professionals, or the Engineer who demands accurate leveling every time. AutoLevels set up fast, are easy to use, and save time and money on every job.
A link is exactly ?66⁄100 of a foot, or exactly 7.92 inches or 20.1168 cm. The unit is based on Gunter's chain, a metal chain 66 feet long with 100 links, that was formerly used in land surveying.
Gunter's chain (also known as Gunter's measurement) is a distance measuring device used for surveying. It was designed and introduced in 1620 by English clergyman and mathematician Edmund Gunter (1581–1626). It enabled plots of land to be accurately surveyed and plotted, for legal and commercial purposes.
A fathom is a unit of length in the imperial and the U.S. customary systems equal to 6 feet (1.8288 m), used especially for measuring the depth of water. There are two yards (6 feet) in an imperial fathom.
A furlong is a measure of distance in imperial units and U.S. customary units equal to one eighth of a mile, equivalent to 7920 inches, 660 feet, 220 yards, 40 rods, or 10 chains. Using the international definition of the inch as exactly 25.4 millimetres, one furlong is 201.168 metres.
Derived from Middle English aker (from Old English aecer) and akin to Latin ager (“field”), the acre had one origin in the typical area that could be plowed in one day with a yoke of oxen pulling a wooden plow. The Anglo-Saxon acre was defined as a strip of land 1 × 1/10 furlong, or 40 × 4 rods (660 × 66 feet).
English-speaking world
On land, the league is most commonly defined as three miles, though the length of a mile could vary from place to place and depending on the era. At sea, a league is three nautical miles (3.452 miles; 5.556 kilometers).For any chemical chain reaction, the chain length is defined as the average number of times that the closed cycle of chain propagation steps is repeated. It is equal to the rate of the overall reaction divided by the rate of the initiation step in which the chain carriers are formed.
