AATCC 183 pdf free download

AATCC 183 pdf free download.Transmittance or Blocking of Erythemally Weighted Ultraviolet Radiation through Fabrics.
1. Purpose and Scope
1.1 This standard test method is used to determine the ultraviolet radiation blocked or transmitted by textile fabrics intended to be used for UV protection.
2. Principle
2.1 The transmission of ultraviolet radiation (UV-R) through a specimen is measured on a spcctrophotomctcr or spectroradiometer at known wavelength intervals.
2.1.1 The ultraviolet protection factor (UPF) is computed as the ratio of the erythemally weighted ultraviolet radiation (UV-R) irradiance at the detector with no specimen to the eiythcmally weighted UV-R irradiance at the detector with a specimen present.
2.1.2 The erythemally weighted UV-R irradianec at the detector with no specimen present is equal to the summation between wavelength intervals of the measured spectral irradiance times the relative spectral effectiveness for the relevant erythemal action spectra times the UV-R weighting function of the appropriate solar radiation spectrum times the appropriate wavelength interval.
4. Safety Precautions
NOTE: These safety precautions are for information purposes only. The precautions arc ancillary to the testing procedures and arc 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. Manufacturers MUST be consulted on specific details such as material safety data sheets and other manufacturer’s recommendations. All OSI-IA standards and rules must also be consulted and followed.
4.1 Under any circumstances, do not look directly at the equipment and materials that may increase the light source intensity, such as mirrors.
4.2 Good laboratory practices should be followed. Wear prcscnbed safety glasses in all laboratory areas.
7. Instrument Verification and Calibration
7.1 Calibration. Calibrate the spectrophotometer or spectroradiomctcr according to manufacturer instructions. The use of physical standards arc recommended for validating the measurement of spectral transmittance.
7.2 Wavelength scale. Calibrate the wavelength scale of the spectrophotometer or spectroradiometer using the spectral 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 Practice E 275, Standard Practice for Describing and Measuring Pcrformancc of Ultraviolet, Visible and Near-Infrared Spectrophotometers.
7.2.1 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 O°/ 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. Specimens
8.1 Test a minimum of two (2) spceimens from each sample. Cut each specimen at least 50 x 50 mm (2.0 x 2.0 in.) or 50 mm (2.0 in.) in diameter. Avoid distoning the specimen during preparation and handling.
8.1.1 Should the fabric have areas of different colors or structure, test each color or structure if its size is sufficient to cover the measuring port.
8.2 See Appendix AS for specimens exhibiting fluorescence.
9. Conditioning
9.1 For dry specimens.
9.1.1 Prior to testing, precondition and condition the test specimens as directed in ASTM D 1776, Conditioning Textiles for Testing. Condition each specimen for at least 4 h in an atmosphere of2l ± 1°C (70 ± 2°F) and 65 ± 2% RH by laying each test specimen separately on a screen, perforated shelf or conditioning rack.
AATCC 183  pdf download.