ISO 291 sets out specifications for the conditioning and testing of all plastics and all types of test specimen at constant atmospheric conditions. Special atmospheres that apply to a particular test or material, or that simulate a particular climatic environment, are not included.
In practice, ISO 291 is the reference a plastics laboratory uses to define the constant atmosphere in which specimens are conditioned and then tested. When setting up a test, check whether the product or test standard for the material calls for one of the ISO 291 atmospheres or for a special atmosphere, since special atmospheres fall outside this document. Record the atmosphere used with the results so they can be compared with other test sessions.
Holding a constant conditioning atmosphere calls for an enclosure with controlled temperature and humidity. Our NG-EC Series environmental test chambers are used for conditioning plastic specimens to ISO 291. If you need help matching ISO 291 requirements to your parts or setup, contact our team.
