DISTANCE MEASURING INSTRUMENT

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 DISTANCE MEASURING INSTRUMENT

To know about the distance measuring instrument first off all we have to know about distance.

What is distance?

It is length between any two specific point which you want to measure or we fixed on ground.
and the instrument which used to measure the length are the distance measuring instruments. 

Distance can be measured directly and indirectly with the help of instruments. 
On the basics of direct method and indirect method instruments are categorized into two parts,
i.e.   
A.  Direct Distance measuring instruments
B.  Indirect Distance measuring instruments

Direct Distance measuring instruments:

Direct distance measuring instruments are those types of instrument which used to give the distance / length between any two point at the time of measurement on the field directly without any mathematically calculation or without help of any other instruments.

Direct distance measuring instruments are:
1. Chain
2. Tape

Chain:

It is direct distance measuring instrument which is made up of iron or steel. It is commonly used for measurement of distance where a very high accuracy is not required. It consists of a number of large links made up of galvanized mild metal wire of 4mm diameter.

Each end of the links is bent into a loop. These links are connected in series by small connecting links. The connecting links consist of three rings, the outer two rings are of oval-shape whereas the central ring is circular. These connecting links provide flexibility to the chain. The joints of the links are usually open but sometimes these are welded.

The two ends of the chain have brass handles which are used for pulling and dragging the chain. The handles have swivel joints to provide flexibility so that it is possible to swivel the handle round the eye bolt without its twisting.

The length of the link is measured from the centre of the connecting central ring to the centre of the next connecting central ring. The end links are smaller than the other links because the length of the brass handles is included in it. The overall length of the chain is taken as the distance between the outsides of the two handles when the chain is fully stretched.

 Types of chain:


Tape:


Types of tape:




 


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