Measuring large items accurately i.e. +-0.1mm

[bogstandard]

You will most probably find that your 150mm micrometer will only measure 125 to 150mm, but within that range, the reading will be spot on.

Almost any cheapo digital vernier would be able to measure what you want to the tolerances you require. Aldi very regularly have them on special offer for well under a tenner. They are accurate to around 0.05mm (0.002").

Bogs

[John S]

Do you mean 80 to 100 MM or 80 to 100 CM which is 800 to 1,000 mm?
You can get 1 metre long verniers but they are expensive.

BTW only the BBC and dressmakers use Centimeters