Use this spreadsheet to determine how accurate your mount/telescope is pointed at the celestial north pole.
Compass’ only tell us which direction the magnetic north pole is. Polaris (the “north” star) gives us a close (less than one degree) approximation. But to use a mount/telescope for taking images, you want to be parrallel within several arcminutes (or even arcseconds) of the celestial polar axis.
Before using this spreadsheet, determine how the knobs on your mount/telescope change the azimuth and altitude. For instance, if turning the altitude knob twenty turns changes the altitude five degrees you now know that the altitude changes 900 arcseconds for each turn, or 15 arcminutes for each turn. Likewise, determine the effect of the azimuth knob.
This spreadsheet is based on a paper written by Ralph Pass. It is included below the spreadsheet. Read the paper for an explanation of how to use this with a GoTo mount/telescope. More
Here is a PDF file of a method of a two star polar alignment by Ralph Pass
You can download the file by saving it to your computer’s hard drive – when you hover over the bottom right of the pdf the choices should show up. If you have your browser set to not load files, you may need to right click and allow adobe pdf to run.