Measurement @D tool

I am reviewing a drawing document in PDF and want to be able to find the distance between any two objects. A scale is needed to create dimensional information between any two points. To do this I click on the distance tool in Acrobat 8 prof which opens the scale parameter window. Then I enter different values and see how accurate the dimension between two known points is. When I finally match the scale parameters to give me the proper distance, I can then dimension any two objects on the drawing. I can then close and open the same file and find the scale to remain unchanged. You can also change the magnification and the scale remains accurate. This is great. When I turn off the program and then open it again, the distance measurement tool has forgotten the settings I gave it. My question is how do I attach this measurement information to the particular drawing in question so that I do not have to enter the scale again. Can I take the piece of paper with the scale parameters off the wall?