So your 8" line becomes 32'... or exactly 48 times larger.  And the viewport scale you're working in is 1/4" = 1'-0"... which (in old school language) represents a scale factor of 48. 

Dave, doing that.. trying to sniff out the inconsistency that's killin me. I'll see if my model space (A-48) dimstyle will let me get my job done instead. I prefer to have it all in paper space, especially if I do a blowup of a blowup.

Edited by AmarARCH - 31.Oct.2012 at 18:49

Ok, here's what I suspect might be happening:  Is there a scale factor of 48 assigned in the Measurement scale on the Primary Units tab of that PS-48 dimstyle?  The box that says "Apply to layout dimensions only" may also be checked.  But even if it isn't you will probably still see the same thing.  If you change the 48 back to 1 you're dim values should correct themselves.

The Measure command will always give the real length, and that's true if you draw a 10" line in paper space and measure it, or if you measure an 8" line on the model in paper space.  The viewport scale factor doesn't have any effect on the Measure tool.

I always use annotative dimension styles now and have a set of them configured in my basic template files for Civil work (Decimal-Feet) and for Architectural (Architectural-Inches).  In all cases the Measurement Scale setting is 1.  And with annotative scaling DIMSCALE=0.  These two styles, and their children styles, are all I really need.  They work with everything.  And I do all my plotting from paper space layouts.

If none of this is helping we may need to know a little more about that DIMSTYLE for PS-48.

Attached is a little example I put together that might help a little more.  Both viewports in this example have a scale of 1/4" = 1'-0".

Dave.

uploads/20121101_071744_dimstyles.pdf


Edited by heinsite - 01.Nov.2012 at 07:19

Great!  Glad this wasn't any more more painful than it was.