Micro-Optics Ltd

Vacuum/UHV/Mechanics

Pressure and atmospheric air

Pressure is an intensive physical value of thermodynamic systems and also a linear field value. Its formula symbol is p which is derived from the international standards system (also known as SI (abbreviation for the French Systeme international d'unites). This incorporates the modern metric system and is by far the most widely used system of standards for physical units.

Partial pressure is the pressure which can be assigned to a compound gas as in this example. Partial pressure is the same as the total pressure which the components would exert if filled exclusively with the total volume.

Total pressure is the same as the total of the various partial pressures.

Work areas of vacuum pumps

illustration of vacuum ranges

In conjunction with competent partners we are now able to improve and extent scanning electron microscopes (even in difficult situations) in terms of their vacuum systems.

•  Improvement and extension of the pump system
• Improvement and expansion of the vacuum ducts

To do this we may use turbo pumps, getter-ion pumps in the high vacuum range as well as diaphragm pump combinations in the pre-vacuum range. In one specific order, for example, a JEOL JSM 6100 scanning electron microscope was modified such that an LaB6 cathode in the 10-7 mbar range could be used in it.

Complete view - please click on picture

Over the last few years we have been faced with several problems relating to ultra-high vacuum (UHV). We have managed to identify solutions to these problems by means of extensive series of measurements and tests. In almost every case the UHV range of 10-8 PA was not reached. There are three principle reasons for this:

• So-called internal leaks
• Leaks to the “outside”
• Used pumps (IGP)

Do you have any questions on this? We can help!