The rise-and-fall system; The collimation system;
- seotskpak
- Nov 19, 2016
- 2 min read
The reduced level of the line of collimation is said to be the height of the instrument. In this system, the height of the line of collimation is found out by adding the back-sight reading to the RL of the BM on which the BS is taken. Then the RL of the intermediate points and the change point are obtained by subtracting the respective staff readings from the height of the instrument (HI).The level is then shifted for the next setup and again the height of the line of collimation is obtained by adding the back-sight reading to the RL of the change point (which was calculated in the first set up)So, the height of the instrument is different in different setups of the level. Technical Data used in the field explained in civil surveyor course in rawalpindi. Two adjacent planes of collimation are correlated at the change point by an FS reading hem one setting and a BS reading from the next setting. It should be remembered that, in this system, the
RLs; of unknown points are to be found out by deducting the staff readings from the RL of the height of the instrument. Consider; RL of HI in 1st setting = 100.000 + 1.255 = 101.255, RL of A = 101.255 – 1.750 = 99.505, RL of HI in 2nd setting = 99.105 + 2.750 = 101.855.RL OF c = 101.855 – 1.950 = 99.905.RL of D = 101.855 – 1.550 = 100 .305 and so on. Some more details of civil surveyor course in rawalpindi are as under. Arithmetical check; FS = Last RL – RL The difference between the sum of back sights and that of foresights must be equal to the difference between the last RL and the first RL. This check verifies the calculation of the RL of the HI and that of the change point. There is no check on the RLs of the intermediate points.
The rise-and-fall system
In this system, the difference of level between two consecutive points is determined by comparing each forward staff reading with the staff reading at the immediately preceding stag reading, a rise is said to have occurred. The rise is added to the RL of the preceding point to get the RL of the preceding point to get the RL of the forward point. . TSK Training for Skills and Knowledge is the best institute in Rawalpindi Islamabad for Pakistani Students who wants to join civil surveyor course in islamabad.
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