Subject materials to "abnormal" conditions (extreme heat or humidity) to predict how they will perform in actual service environments. Standard Laboratory Atmosphere
This is the most common standard associated with these digits. It establishes the mandatory environmental "pre-conditioning" required for plastic specimens before they undergo mechanical, thermal, or electrical testing. astm d61821 pdf
Testing performance in extremely high-humidity environments. Key Technical Specifications Subject materials to "abnormal" conditions (extreme heat or
Once you have successfully downloaded the correct , proper usage is critical for compliance. Testing performance in extremely high-humidity environments
Because the molecular structure of polymers is highly sensitive to ambient temperature and atmospheric moisture, skipping or altering the conditioning phase invalidates standard testing. Authentic copies of the document can be searched and officially acquired via the ASTM International D618-21 Product Page. Why Conditioning Matters in Plastic Testing