AATCC 183:2020 pdf download.Test Method for Transmittance or Blocking of Erythemally Weighted Ultraviolet Radiation through Fabrics
5. Safety Precautions
NOTE: These safety precautions are for information purposes only. The precautions are ancillary to the testing procedures and are not intended to be all inclusive. It is the user’s responsibility to use safe and proper techniques in handling materials in this test method. Users MUST consult manufacturers on specific details such as safety data sheets and other recommendations. Consult and follow all applicable OSHA standards and rules.
5.1 Under any circumstances, do not look directly at the equipment and materials that may increase the light source intensity. such as mirrors.
5.2 Follow good laboratory practices. Wear prescribed safety glasses in all laboratory areas.
8. Instrument Verification and Calibration
8.1 Calibration. Calibrate the spectrophotometer or spcctroradiometcr according to manufacturer instructions. The use of physical standards is recommended for validating thc measurement of spectral transmittance.
8.1.1 When running a wet sample place the plastic wrap over the port and repeat calibration.
8.2 Wavelength scale. Calibrate the wavelength scale of the spectrophotometer or spectroradiometer using the spec- ti-al emission lines of an electrical discharge in mercury vapor. The wavelength calibration of a spectrophotometer can be performed using the absorption spectra of a holmium oxide glass filter. Reference wavelengths for both mercury arc emission and holmium oxide absorption are provided in ASTM E275.
8.2.1 Transmittance scale. Set the transmittance scale to a 100% value by operating the instrument without a sample in the optical path: therefore, referenced to air. The 0% value can be subsequently verified by fully obstructing the sample beam path with an opaque material. Validate the linearity of the transmittance scale by means of either calibrated neutral density filters or calibrated perforated screens supplied by the instrument manufacturer or standardizing laboratories.
8.3 Verification checks on the operation of the test and the apparatus should be made and kept in a log. The use of a verification fabric is recommended at least once a month unless no testing is to be performed that month.AATCC 183 pdf download.