Convert dgn files from feet to survey feet

Question

I remember doing something along this line a LONG TIME AGO. But I can't remember anything anymore. I have some dgn files that need to be converted from feet to survey feet. 
 Can anybody help or point me in the right direction?

Tim Hickman · Accepted Answer

ok here is what I have: 
The file is in international feet, no matter what your units.def is set to. If you take a look at the link I provided it will give you a bit more understanding what exactly is happening. What the units.def is doing for you, is limiting the choice for a master unit in the design file. 
The two things I would do are, get the original units.def file back into place and then set the file to survey feet. 
Setting the file to survey may not be all that is needed in the file. 
For example: I drew a line that was 5000 feet long in the file. I then changed the master unit to survey feet (as I have this choice from my units.def file). When I measure the length after this change it was 4999.99 survey feet (which is correct - a survey foot is longer than an international foot). If you are ok with this change as it is now the correct length in survey feet, you are done. BUT - if you now want the original length to be the same units, but in survey feet, the file needs to be scaled. You can do this several ways. You can physically scale the whole file OR in your case since you used 10000/foot as your resolution, you can simply change this to 10000/survey foot and the previous 5000 foot measurement will now be 5000 survey foot. 
Don't forget to save settings after these changes ! 
I hope this makes sense and helps you with the issue/question you had.

Tim Hickman · Answer

what do you mean by convert ? Simply change the units from feet to survey feet. It would be the same as changing the units from feet to meters.

Tim Hickman · Answer

this may help: 
 
 communities.bentley.com/.../survey-feet-vs-international-feet

Convert dgn files from feet to survey feet

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