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Vacuum-Compatibility and Ultraclean Applications




What is outgassing?

Outgassing is the process in which some material will release a gas or volatile component that is trapped, dissolved, frozen or absorbed in the material. The outgassing increases when the material is exposed to heat and or a vacuum. This gas will eventually condense on other materials and could render them inoperable.


Why does it matter?

Outgassing is usually most relevant in vacuum applications, where the vacuum causes some materials to release constituent material. Outgassing becomes a problem if a thin film of those outgassed materials condenses on nearby surfaces. Such a film poses major challenges in highly sensitive applications, such as optics, where cleanliness is of utmost importance. A material with low outgassing is essential to ensure the performance of space optics.


About TML and CVCM

TML: Total Mass Loss
CVCM: Collected Volatile Condensable Materials

The TML and CVCM values are obtained through a specialized standardized test, where a sample is heated in a vacuum chamber. The TML represents the difference in weight before and after the test. CVCM values involve a cooled plate in front of the heated sample in the vacuum chamber. The increase in weight of the plate represents the CVCM.

NASA Low Outgassing: NASA considers material to be low outgassing if the maximum total mass loss (TML) is less than 1.0 percent and maximum collected volatile condensable material (CVCM) is less than 0.10 percent. NASA's website contains a summary of a wide range of low-outgassing materials.

TML CVCM
< 1.0 % < 0.1 %


PLX's Space-Qualified Optics

PLX has been producing space-qualified instruments and components for over 40 years and covers a wide range of applications.

PLX’s space heritage dates back to July 1975 when the company provided hollow retroreflectors to the Apollo-Soyuz Russian-American space hookup program. The units were used in the docking procedure to align the two vehicles. The program included both joint and separate scientific experiments and provided useful engineering experience for future joint US–Russian space flights, such as the Shuttle–Mir Program and the International Space Station.


PLX is a registered ISO 9001 company and has a Class 100 cleanroom.


Please refer to PLX Retroreflector Selector Chart to learn how our retroreflectors rank in vacuum compatibility. We can also engineer and manufacture solutions that meet your vacuum compatibility requirements.


Please complete our RFQ form or call us today to discuss your specific requirements.

PLX Inc.
40 West Jefryn Blvd.
Deer Park, NY 11729
Phone: 631-586-4190
Fax: 631-586-4196