Indicator on thumb screw indicates approximately 1mm diameter.
- Break carbon rod about 50mm - 75mm long.
- Insert flat end into the hole in the base of the carbon rod sharpener.
- Gently push the rod up into the cutter while rotating it in a clockwise direction. Hold the carbon rod sharpener so that any carbon dust falls into a waste container.
The formed tip should range from 0.4mm to 2mm in length to give the approximate film thickness shown in the table below.
It is often helpful to use a paper or porcelain indicator near the specimen. Approximate grey scale is indicated in the last column of the table.
|IF:||M = mass evaporated W = mass per unit area||W=||M|
|D = distance to specimen||W= and t||t p|
|t = thickness (of carbon)p = density (of carbon)||=V=||4o D2p or 2l|
|r = radius of carbon rod l = length of carbon rod v = volume of carbon evaporated||M=||Vp and M = or 2 1p|
|t=||or 2.1 = r2.1|
Using the carbon rod sharpener as set, r = 0.5mmFor convenience, D = 100mm (with added block or platform) and the following table can be used directly.
(Refer to electron microscopy textbooks by Hall, Kay, Pease and others.)