Methods of booking and reduction of levels

1. Using rise and fall method

In this method booking is done in the following manner,

1) On any page of book, the first reading is always a B.S and last reading is always a F.S. If you are not getting F.S as last reading on each page, then it means you have done mistake while booking readings.
2) From the B.S next F.S is subtracted. If the answer is positive (+), it will be Rise and if the answer is negative (-) it be Fall and put that reading in respective box.
3) In the above table, I have assumed that Reduce Level (R.L) of point A is 100.0 and you can see R.L of point B is 100.67, which shows that point B is .67 units higher than point A.

In case of numerous readings, the check should be applied at the end of each page while booking reading,

∑ (B.S) - ∑ (F.S) = ∑ Rise - ∑ Fall = R.L of last point - R.L of first point; 5.620 - 4.950 = 1.37 - 0.70 = 100.67 - 100.00 = 0.67 = 0.67

2. Using height of collimation method (H.O.C)

For this method use the following formulas,

R.L + B.S = H.O.C and H.O.C - F.S = R.L

All other considerations are same as Rise/ Fall method. Below check have applied,

∑ (B.S) - ∑ (F.S) = R.L of last point - R.L of first point = 7.2 - 7.8 = 99.4 - 100 = -0.6 = -0.6