External conditions of material, such as moisture, temperature, and time of exposure, may greatly affect the results in the case of material testing. An example is the plastics that can swell or become soft in hot weather, the textiles that can absorb or lose moisture due to the humidity, and the wood products that may become warped or shrink if they are not conditioned. ASTM standards are defined as a set of standards on conditioning and testing atmospheres that introduce uniform conditions in which test data can be considered as reliable in design, manufacturing, and quality control.
Key ASTM Standards
ASTM D618 addresses standard conditioning of plastics with the assurance of the sample reaching equilibrium moisture content before testing.
ASTM D1776/D1776M outlines the standard conditions of conditioning and testing atmosphere required for the correct determination of fabric characteristics.
ASTM D685 in paper and packaging provides procedures to condition paper and paperboard to remove the variations in moisture.
ASTM E171 is used as a broad guide to condition test specimens with a wide variety of materials.
ASTM D4933 shows more specific means of controlling temperature and humidity in the test of wood products.
ASTM C511 gives specifications for the storage and conditioning of cement, mortar, and concrete specimens.
ASTM D1349 provides the standard test temperature for rubber materials. These standards are, together, a broad outline of testing condition control throughout industries.
Methodology
The procedure of the creation of standardized conditions of testing usually presupposes preconditioning the specimens to be tested in controlled conditions. This can be the storage of materials at a certain temperature and relative humidity until equilibrium is reached. Then, testing is done under the same or specified environmental conditions, described under the appropriate ASTM standard. Such parameters as the conditioning period, air flow, and equipment setting are very rigorous to ensure that environmental variability does not affect the result.
Applications
The conditions of standardized testing are obligatory in industries that are evidently sensitive to the environmental factors on performance. The plastics and polymers are subject to conditioning, whereby the results remain consistent if they are subject to moisture. Standard test conditions in textiles have ensured repetition of shrinkage, strength, and dyeing properties. The paper and packaging industries make use of conditioning to give reliable printing performance and strength. Where the construction materials used in this instance are concrete or mortar, then the very conditioning will give the right strength and durability values.
Importance
ASTM standards are important to the testing conditions in that they can eliminate the uncontrollable factors, and the results obtained are reproducible across labs. These standards facilitate quality control within industries, adherence to regulatory measures, and the production of materials applicable to actual performance in life by specifying the precise environment and conditioning procedures. The standardized testing conditions would also bring about uniformity and dependability in the results generated, and it would be difficult to compare the results and ensure that a product is doing well. Lastly, ASTM standards present certitude in material testing, which is useful regarding innovation and safety in different industries.
