School of Physics Lecture Demonstration Manual

Og-2 Strain Polarisation

Published: Wednesday 15 March 2006 - Updated: Monday 28 March 2011

Aim

To demonstrate strain birefringence.

Apparatus

Diagrams

Click on pictures to enlarge.

Strain Polarisation Pic

Strain Polarisation Pics

Description

The perspex models and the strained glass (caused by rapid cooling) are placed on the overhead projector with the polaroids in the crossed position. Strain present in the glass or induced in the perspex causes the object to become anisotropic and birefringent. This results in visible stress lines due to interference colours.

Safety notes

Electrical safety 

Maintenance 

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