AATCC 203-2016 Light Blocking Effect of Textiles: Spectrophotometric Method.
4. Safety Precautions NOTE: These safety precautions are for information purposes only. The pre- cautions are ancillary to the testing proce- dures and are not intended to be all inclu- sive. It is the user’s responsibility to use safe and proper techniques in handling materials in this test method. Manufac- turers MUST be consulted for specific details such as safety data sheets and other manufacturer’s recommendations. All OSHA standards and rules must also be consulted and followed.
4.1 Good laboratory practices should be followed. Wear eye protection in all laboratory areas.
4.2 The manufacturer’s safety recommendations should be followed when op- erating laboratory testing equipment.
5. Uses and Limitations
5.1 This test is performed under controlled laboratory temperature and relative humidity conditions. While the test may be performed at alternative condi- tions, such as household ambient temper- ature and relative humidity, for comparison of results, the same conditions must be used.
5.2 The light this test is performed with is from a xenon lamp. Different light sources may be used and results may, therefore, also be different, such as with spectrophotometric instruments with band width infrared (IR) capacity.
6. Apparatus and Materials
6.1 Spectrophotometer with transmis- sion measuring capability with a means of precisely mounting and anchoring a specimen in the transmission holding clamp.
6.2 Means of covering reflectance or external port with a white standard tile to establish the onehundred percent trans- mission standard and to complete the sphere for further transmission readings. 6.3 Means of blocking transmission to determine zero percent transmission.
6.4 If the spectrophotometer is equipped with adjustable ultraviolet en- ergy, standardize the amount of ultraviolet energy in the spectrophotometer light source (see 14.1).
7. Sampling
7.1 Take five representative test speci- mens from the sample. Increase the num- ber of specimens accordingly to include different areas that may have varying light transmission characteristics within the total sample area. Textiles such as long repeat jacquards may require a larger number of specimens in order to obtain a more representative sample. Textiles containing large repeats of alter- nating diaphanous and opaque areas may have the light blocking effect of each area sampled separately.
8. Test Specimens
8.1 Each specimen should be large enough to fit onto the specimen holding frame and completely cover the transmis- sion port of the spectrophotometer.
8.2 Take multiple specimens to provide an appropriate random sample from different width and length areas of the fabric, not taking any specimens from within 10% of the width from the sel- vedge or machine edge.AATCC 203 pdf download.