B5 practical: Factors affecting R (pencil) support page
All that is needed for this experiment is a multimeter, ruler, micrometer and a pencil and paper. Maybe I'm going a bit over the top giving 3 examples of different ways of doing this but every time I tried the different methods I found problems (mainly due to making contact with the sample material). This method seemed like the most dubious but actually gave some of the best results with quite a good correlation...