Lecture3 Mailed
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Transcript of Lecture3 Mailed
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7/25/2019 Lecture3 Mailed
1/13
LINEAR MEASUREMENTS
The horizontal distance between points, is required to
be measured in order to prepare plan or map of the area
surveyed.
There are various methods of making linear
measurements and their relative merit depends uponthe degree of precision required.
They can be mainly divided into three heads
1. Direct Measurements
. Measurement by !ptical means
". #lectro$magnetic Methods
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D%'T M#()*M#+T)
Distances are actually measured on the ground with thehelp of chain or a tape or any other equipment.
!-T%'( M#T/!D)
!bservation are taken through a telescope andcalculations are done for the distances e.g. intacheometery or triangulation
##'T&!$M(0+#T%' M#T/!D)
Distances are measured with instruments that rely onpropagation, reflection and subsequent reception of either
radio waves, light waves or infrared waves.
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D%'T M#()*M#+T)
1. -acing
. Measurement with passometer
". Measurement with pedometer
. Measurement by odometer and speedometer
2. 'haining
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%+)T&*M#+T) 3!& '/(%+%+0
1. 'hain or Tape
. (rrows
". -egs
. &anging &ods
2. -lum bob
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'/(%+
)traight links of galvanised mild steel wire bent into
rings at the ends and 4oined each other by three small
circular or oval wire rings.
ength of a link is the distance between two
consecutive middle rings.
ength is from outside of one handle to the outside of
the other handle.
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5arious Types of 'hains
Metric 'hains
0unter6s 'hain or )urveyor6s 'hain
#ngineer6s 'hain
&evenue 'hain
)teel 7and or band 'hain
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Metric 'hains %) 18 92 : 1; m length