Ramsden Surveying Instrument

RAMSDEN SURVEYING INSTRUMENTS:

The Ramsden surveying instruments are those constructed by Jesse Ramsden and used in high precision geodetic surveys carried out in the period 1784 to 1853. This includes the five great theodolite great in name, great in size and great in accuracy—used in surveys of Britain and other parts of the world. Ramsden also provided the equipment used in the measurement of the many base lines of these surveys and also the zenith telescope used in latitude determinations.

Gyrotheodolite

GYROTHEODOLITE:

In surveying, a gyro theodolite is an instrument composed of a gyroscope mounted to a theodolite. It is used to determine the orientation of true north. It is the main instrument for orientation in mine surveying and in tunnel engineering, where astronomical star sights are not visible and GPS does not work.

HISTORY:

In 1852, the French physicist Léon Foucault discovered that a gyro with two degrees of freedom points north. This principle was adapted by Max Schuler in 1921 to build the first surveying gyro. In 1949, the gyro-theodolite – at that time called a "meridian pointer" or "meridian indicator" was first used by the Clausthal Mining Academy underground. Several years later it was improved with the addition of auto collimation telescopes. In 1960, the Fennel Kassel company produced the first of the KT1 series of gyro-theodolites. Fennel Kassel and others later produced gyro attachments that can be mounted on normal theodolites.

 

PRICE:

$2000-2500 or 140000-180000 PKR

Vernier Theodolite

VERNIER THEODOLITE:

The vernier theodolite is also known as a transit. In a transit theodolite or simply transit the telescope can be rotated in a vertical plane. Earlier versions of theodolites were of the non-transit type and are obsolete now. The function of vernier theodolite is same as other theodolites. It is used to measure angles.

PARTS OF INSTRUMENT:

1. Levelling head
2. Limb or lower plate
3. Spindles
4. Upper plate
5. Standards or A-frame
6. Level tube
7. Compass
8. Telescope
9. Vertical circle
10. Plumb bob
11. Tripod

  

PRICE:
$300 USD or 42000 PKR

Plane Table

PLANE TABLE:

A plane table is a device used in surveying and related disciplines to provide a solid and level surface on which to make field drawings, charts and maps.

USES:

In use, a plane table is set over a point and brought to precise horizontal level. A drawing sheet is attached to the surface and an alidade is used to sight objects of interest. The alidade, in modern examples of the instrument a rule with a telescopic sight, can then be used to construct a line on the drawing that is in the direction of the object of interest.

METHOD OF USING:

1. Radiation Method
2. Intersection Method

Blog Links

Blog Links

• http://instruments.simplesite.com
• https://ahmm65177.wixsite.com/eng-sur
• https://nediansurveyor.wixsite.com/surveying
• http://ehtishamsiddiqui3.wixsite.com/surveyhelper

links

Links for further detail.

•                 https://www.orbitals.com/self/survey/chain/chain.htm 
•                   https://civilseek.com/tacheometric-surveying/
•           https://www.merriam-webster.com/dictionary/cosmolabe
•           http://www.finedictionary.com/Graphometer.html
•           https://www.engineersupply.com/theodolites.aspx
•          //www.gim-international.com/content/article/robotic-theodolites-rts
•           http://www.johnsonlevel.com/News/TheodolitesAllAboutTheodo
•            http://kotsanas.com/gb/exh.php?exhibit=1301002
•            http://lensaticcompass.blogspot.com/2008/09/what-is-lensatic-compass.html
•            https://theconstructor.org/surveying/electronic-distance-measurement-               instrument/6576/
•           https://theconstructor.org/surveying/how-to-use-planimeter-parts/14821/
•           https://www.engineersupply.com/automatic-levels.aspx
•           https://www.aboutcivil.org/what-is-phototheodolite

Gunter Chain

                               GUNTER'S CHAIN 

DEFINATION:

 It is a distance measuring device used for chain surveying. 

Chain survey is the simplest method of surveying. In this survey only measurements are taken in the field, and the rest work, such as plotting calculation etc. are done in the office. This is most suitable adapted to small plane areas with very few details.

Market Value:

Its price in US dollar is $20 to $25 in PKR 3000 to 4000.