The stage graticule will be 1mm in total length, and will probably be divided into 100 segments. (see images below).jimmymac2 wrote: . . . I think my problem now is the fact that I don't know how long 0.01mm is on a 0.01mm scale!! There isn't a label saying "this length is 0.01mm" or anything like that.
There won't be any measurement numerals shown, as the scale is too tiny to engrave them.
However, 1mm = 1000µ, and one segment width on a graticule divided into 100 segments will be equal to 10µ.
So, if you draw a measurement line that is the width of one segment, the software should say that the line is 10µ in length.
If you draw a measurement line between 20 segments, the software should say that the line is 200µ in length.
If you draw a measurement line between 30 segments, the software should say that the line is 300µ in length.
If you draw a measurement line between 50 segments, the software should say that the line is 500µ in length.
Note that in my photo, the line that should read 500µ is out by 2µ, as it is saying 498µ.
(Maybe inaccurate calibration - or more likely, I didn't draw the measurement line between the segments accurately enough!).
NB: When calibrating, it is always best to measure as much of the graticule length as possible, rather than measuring between just a few segments. That way, there will be less margin of error.
Note also that if you start your measurement line at the left hand edge of a segment mark-line, then you should finish the line at the left hand edge of the relevant mark-line. (Otherwise you will actually be measuring the correct distance plus the thickness of one mark-line, making your calibration slightly inaccurate).