Collimation method to reduce a leveling field book page written By Rolita Rode

▼1

▼1

Name BM1 a b b bd 1 c bd2 d e f g h BM 2

BS

▼1

IS 1.216 ◄5

▼1 FS

6► 0.025 ◄6 1.555 ◄6

1.386 ◄7 6► 3.625 1.235 3.655 2.126 2.605 1.094 1.125 1.394

2.508 1.196 3.566 0.506

3.628 0.484

2↗

10.743 ▲3

-1.145

▲4

11.888 ▲3

▼11 Ht of collimation Reduced Height 5 ► 107.582 ◄ 6► 107.557 6► 106.027 106.460 7► 105.074 ▲7 102.835 106.499 105.264 106.588 102.933 108.208 106.082 105.603 107.114 105.705 104.580 104.311 10 & 16► 105.221

▼16 check

Misclosure Correction

▼12 ▼14 Corr Fin. Height 0.007 0.007 0.007 0.014 0.014 0.021 0.028 0.035 0.035 0.035 0.042 0.042

106.366 ◄16 107.564 106.034 105.081 102.849 105.278 102.954 106.110 105.638 107.149 104.615 104.353 105.263 ◄10

0.042 ◄10 0.007 ◄11 -1.145 ◄16

1 The first 4 columns is what you completed in the field its called the field entries This must be written in the field in pencil the rest must be written in pen 2 Draw a line across the columns underneath the last FS as shown above 3 Add up the BS readings and the FS readings and write the answer below the line do this in the field 4 Subtract the answers in no3 ΣBS -ΣFS and write the answer in next the row in the IS colum 5 Take the final height for the first bench and add the first BS reading to this height and write in the collimation height colum 6 Now use this collimation height and subtract the IS readings for all IS in this setup and write the answer in the reduced height colum do this up to the FS 7 For your next setup you need to calculate a new collimation height you take the last reduced height in that colum and add the BS reading to this height and write in the collimation height colum 8 Repeat step 6 and 7 for all the setups 10 Subtract the final reduced height of the last point from the given height of the last point This is your misclosure that must be written as shown including the sign 11 Divide the misclosure by the number of setups to obtain the correction per setup. 12 Apply the correction as follows: for the 1st setup you use the correction per setup until & including the first FS For the 2nd setup you use the correction per setup times 2 for the 3rd setup you use the correction per setup times 3 You continue until the last setup 13 You need to apply the correction to all the IS in that specific setup as well 14 Now add the reduced height and the correction to give you the final height 15 Do the checks as the lecturer instructed you 16 Subtract the first final height from the last reduced height. This must equal ΣBS -ΣFS as check

Collimation Method Explained

Rolita Rodes created a spreadsheet to explain the collimation methods calculations to my students, they found it very usefull, hope that you...