Subtense Bar Method | Tachymetry Methods of Horizontal Distance Measurement | Surveying

Distance by Tachymetry
The subtense bar is a convenient and practical device used for quick and accurate measurement of horizontal distance.
The bar, which is precisely 2 meters long, consists of a rounded steel tube through which runs a thin invar rod.
The procedure for determining the distance between two points consists of setting up the subtense bar at the distant station, and measuring the horizontal angle subtended by the distance between the two targets.
A subtense bar 2.000 meters long is set up near the middle of a traverse line PQ. Using a theodolite set up at P, the angle subtended reads 0°20′ 14“. When the theodolite was transferred and set up at Q, the corresponding subtended angle was observed as 0°23^′ 47". Determine the horizontal length of line PQ.

[@eugineguan2122]

Thank you so much sir for this lesson. It helps a lot. I am taking now fundamentals of surveying and for me it so hard to understand lots of topic in surveying because of no actual teachings due to pandemic. I hope for more videos here sir all about the topics in fundamentals of surveying.

[@asdfopera7661]

Thank you for actually showing the subtense bar tool. My textbook did not show it or provide the formula so the concept didn't make sense until I watched this video.

[@asayilethindwa3209]

You are my favorite sir ❤

[@ericagracesanchez2414]

Thank you po Sir

[@alideya1163]

Thanks a lot 👍

[@carltolentino2044]

Subtense bar is the upper rod reading less than lower rod reading

[@rodalyndaffon1964]

how to input that in the calculator ?

[@JonasClassNotes]

Do you mean the angle?

[@loysaaa2185]

kung paano mo nakua ang 339.81 m 4:29? Iba kasi ang lumalabas sa calculator sana matulungan mo ako dito. Maraming salamat sa video na ito naiintindihan ko na siya kahit papaano.

[@miyuki6541]

Same po iba rin sakin

[@na-nk3pk]

You have to write 0 degree 20 mins 14 sec on calculator . He had written 20 mins 14 sec, Which you copied to get the answer.

[@zianrussellnarvaez3793]

There is a button in the calculator for this, the one with the circle and the 3 apostrophe symbols. Or you search this "Decimal Degrees to DMS Formula".

[@pascuarico-isan446]

Yung distance ba yun na yung horizontal Length sir?

[@ericagracesanchez2414]

opo

[@macmacjohn9790]

Pano po iinput yung angle sa calculator?

[@miyuki6541]

Bakit po iba lumalabas na sagot sa calcu?

[@sorinojanetg.7250]

Paano po yan iniinput sa calculator sir

[@JonasClassNotes]

Saang part ang tinutukoy mo?

[@architecturalworld7678]

Sa cot(20'14"/2) sir paano yun yung 20 at 14 e add ba yun multiply devide or minus.?