Diffraction Standards

Camera Length

80045

80044

The nominal value of the effective camera length of an EM operating in the selected area mode is not sufficiently accurate for any calculations of lattice spacing. The actual value of camera length must be calibrated as the same accelerating voltage and objective lens setting by reference to a known substance with well defined diffraction spacings. The normal specimens are evaporated films on a 3.05 mm grid of aluminum or thallous chloride. The very small crystalline size yields ring patterns suitable for calibration purposes.

Image Rotation

When changing from a selected area image of a specimen to a diffraction pattern, the strength of the intermediate lens is changed, producing an image rotation between the image and the diffraction pattern. The amount of this rotation can be measured by photographing a crystal whose shape gives a clear indication of orientation. A molybdenum oxide crystal is very suitable for this purpose. Evaporated on a 3.05 mm grid.

Measuring Aids

Ultrastructure Size Calculator

A slide-guide-calculator used to determine the real-life size of a structure from a micrograph- in micrometer, nanometer or angstrom units. It computes the real-life dimension/mm at magnifications from 1,000 to 100,000 by introducing a multiplication factor of x² or x^1/2. The magnification range can be extended.

Waterproof card, printed in English, German and French.

Photomicrograph Scale Marker

A slide-ruler used to apply scale marks to photomicrographs. There are four scale lines for producing scale marks of 10 microns, 1 micron, 0.1 micron (100 nm) and 10 nm. The scale marker is also used in measuring the real life size of an object in a micrograph. It is made from a clear flexible plastic and it is protected by an enclosed pouch. Instructions are included. Printed in English, German, and French.

Tip Check and Nioprobe for SPM