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How to Mean an Angle Set

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field-dog
(@field-dog)
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I forgot how to mean an angle set. I only know how to check an angle set to make sure it's within tolerance. Please see the attached file. I check it like this.

FSD - FSR = 2"

BSD - BSR = 3"

(2" + 3") / 2 = 2.5"

I'm < or = to 5", so I'm good.

We have to start writing these angle sets in the field book. Any help would be greatly appreciated.

 
Posted : July 13, 2019 4:06 pm
larry-scott
(@larry-scott)
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FS Dir minus BS Dir = angle Dir
FS Rev minus BS Rev = angle Rev

(Angle Dir + Angle Rev)/2

Angle Dir
302-12-34 minus 00-00-23= 302-12-11

Angle Rev
122-12-40 minus 180-00-24= 302-12-16

Mean angle 302-23-13.5

 
Posted : July 13, 2019 8:21 pm
field-dog
(@field-dog)
Posts: 1429
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Topic starter
 

Thanks!

From my attached file.

354?ø44'24" - 0?ø00'00" = 354?ø44'24"
174?ø44'22" - 179?ø59'57" = -5?ø15'35"
(354?ø44'24" + -5?ø15'35") / 2 = 174?ø44'25"
174?ø44'25" + 180?ø00'00" = 354?ø44'25"ƒ??

Note: Add 180 degrees to mean angle if Angle Dir is > 180 degrees.

?ÿ

 
Posted : July 14, 2019 7:51 am
dave-karoly
(@dave-karoly)
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I'm not able to upload my handwritten calculations...

there are at least two ways to do it:

mean the backsights then mean the foresights. M BS minus M FS equals M angle right. I find this method easier in a field book.

the other way is (FS D minus BS D) plus (FS R minus BS R) divided by 2.

 
Posted : July 14, 2019 10:16 am
larry-scott
(@larry-scott)
Posts: 1059
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Itƒ??s really simpler. Iƒ??d never bother with -5-15-35
Visually the average should be automatic
354-44-24 D 354-44-25 R

Average the seconds. No brained.
134-47-04 D 134-47-10 R

Iƒ??d never see this in a field book.
134-47-04 D -225-12-57 R

 
Posted : July 14, 2019 10:32 am