The inherent resolution of a PSD is very good. It is proven to be better than one part in one million. The performance of a PSD based measurement system is thus limited by its mechanical, optical and electrical components.

To get the best performance you have to consider:

• Modulated light source. Modulation makes it possible to avoid influence of other light sources.

• Stable temperature.

• Mechanical stable system.

• High optical resolution.

• High resolution in division of the sum- and difference signals.

Resolution, optical sensitivity and measurement speed are related to each other in the PSD measurement

system and you have to make the proper choices and tradeoffs for your system. Further information as schematics

of a recommended hook-up is obtainable from your local distributor or from SiTek Electro Optics AB.