Right Angle
Right angle is also olden basic tool made of wood,mild steel sheet,stainless steel with cast iron handle used for various engineering works.actualay it used every where in engineering field.especialy for inner or outer corner checking .it made on right angle (90°)triangle rule that at every step of angle is as at right position. by measurement a famous rule called 3,4,5 here 3 is perpendicular 4 is base and 5 is hyputios.in our field if any surveyor does not know about right angle triangle rule he could not do survey if he know about it he cannot feel difficulty to solve his drawing calculation problems. Some figures showing its right angle.
We can say it is a template of 90 degree or 100 grad having its advantage from centuries to till to date.
Calibration
For first time use it need calibration and also time to time as you feel difference or need satisfaction you can calibrate it the method is showing on the figure below put the right angle in position 1 draw a pencil line forward the top line to position 2 turn the right angle in position 2 back should be at vertical drawn line if top horizontal line is according to forwarded line then it is correct if shows any difference then it is incorrect .here blue line is pencil line
I hope you will have knowledge of basic tool .and pray for to write more of my knowledge for you surveyor?
Thanking you
M Akram Shahid
Thoughts