Jump to content
CIVILERS
Sign in to follow this  
Azhar Shahzad

Booking and Reduction of Levels using Rise and Fall or Height of collimation (H.O.C) Method

Recommended Posts

Using Rise / Fall Method

In this method booking is done in the following manner,

B.S I.S F.S Rise Fall R.L Remarks
2.570 - - - - 100.00 A
3.750 - 1.200 1.370 - 101.37 C.P
- - 3.750 - 0.70 100.67 B
5.620 - 4.950 1.370 0.70 - -
  • 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.
  • From the B.S next F.S is subtracted. If the answer is +ve it will be Rise and if the answer is -ve it be Fall and put that reading in respective box.
  • 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 0.67 = 0.67 = 0.67

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

B.S I.S F.S H.O.C R.L Remarks
2.50 - - 102.50 100.00 -
1.75 1 1.95 102.30 100.55 -
- 2.55 - - 99.75 -
- 2.70 - - 99.60 -
2.95 - 3.10 - 99.20 -
- - 2.75 - 99.40 -
7.20 - 7.80 - - -

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

Share this post


Link to post
Share on other sites
Guest REJMAC

Hi I need a help about this sub

I have a table of H.O.C method and I have to change it to the Rise and Fall method would you please help me 

Share this post


Link to post
Share on other sites

Your content will need to be approved by a moderator

Guest
You are commenting as a guest. If you have an account, please sign in.
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoticons maximum are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×