UV RESISTANCE / PROTECTION UPF- Ultraviolet protection factor rating. Ultraviolet Protection (UPF) 15 – 50+ Test Methods – AATCC AATCC Transmittance or Blocking of Erythemally Weighted Ultraviolet Radiation through Fabrics. standard by American Association of Textile. work, e.g. AATCC with ASTM D and. ASTM D in the United States and EN in. Europe. The Australian Radiation Protection and.
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In spectrophotometers and spectroradiometers where the illumination is polychromatic and the monochromator follows the specimen in the optical path, the artificially high values of transmittance appear at the emission wavelengths of the fluorescing agent.
The use of an illuminating light source that conforms to the spectral distribution requirements for solar simulators will most accurately include the contribution of sample fluorescence to the long wavelength UVA measurement. Wear prescribed safety glasses in all laboratory areas.
Between-laboratory precision has not been established for this test method. In Marchan ul- A1. Avoid distorting the specimen during preparation and handling.
Calibrate the wavelength scale of the spectrophotometer or spectroradiometer using the spectral emission lines of an electrical discharge in mercury vapor. Press and move the specimen from time to time to ensure a good and uniform penetration.
Purpose and Scope 1. If the fabric has low moisture absorption, repeat the soaking and wringing steps. Instrument Verification and Calibration 5.
Note, some samples may not be capable of achieving the specified wet pick-up such as tightly woven synthetic fabrics. The intervals in Table II are in 2 nm.
Uses and Limitations 3. The wavelength calibration of a spectrophotometer can be performed using the absorption spectra of a holmium oxide glass filter. As a means of estimating this property, the method has no known bias. 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.
Prepare only one specimen at a time. The contribution of sample fluorescence on spectral transmittance measurements on certain dyes and whitening agents present in fabrics that may fluoresce could result in artificially high values of spectral transmittance.
The specimen is viewed unidirectionally with an axis not greater than 0. The error due to the fluorescence can be removed by placing a UV transmitting, visible blocking filter after the sample. The use of physical standards are recommended for validating the measurement of spectral transmittance. The precautions are ancillary to the testing procedures and are not intended to be all inclusive.
In this geometry the specimen is illuminated by an internally illuminated integrating sphere. Principle ance transmitted and calculated through air to the average effective UV-R irradiance transmitted and calculated through fabric. Illumination and viewing geometries.
These safety precautions are for information purposes only. The error can be eliminated in either geometry by use of a separate reference beam that traverses its own port opening in the sphere. Thoroughly wet out the specimen in distilled water by placing it flat in the bottom of a beaker and then pour distilled water into the beaker until the specimen is covered. It must be noted that stretching the specimens could change the UPF properties. The cross-sectional area of the viewing beam shall be at least 10 times the dimension of the largest hole in the test material.
The total flux transmitted by the specimen is collected by the integrating sphere. The aaatcc sphere surface is internally coated or constructed using a material that is both diffuse and highly reflecting in the ultraviolet region. Avoid evaporative reduction of the moisture content below the specified xatcc before the actual UV transmission measurements are made.
Precision and Bias The contribution of stray radiation within the instrument, including that due to sample fluorescence, shall produce an error of less than 0.
Apparatus and Materials 8.
UV STANDARD | Determination of the UV Protection Factor UPF
Allow the specimen to remain submerged for 30 minutes. In this geometry the specimen is illuminated with an unidirectional beam whose axis is not greater than 0. Calibrate the spectrophotometer or spectroradiometer according to manufacturer instructions.
Any ray of this beam shall not exceed 0. The spectrophotometer or spectroradiometer shall have a spectral bandpass of 5 nm or less over the spectral range of nm or less to nm or more. However, the techniques for stretching the specimens are not part of this method and are addressed in a separate test procedure.
Filter, Schott Glass UG11 see All OSHA standards and rules must also be consulted and followed. The intervals in Table I are in 2 nm. However, the decrease in transmission of the filter with increasing wavelength may reduce the usefulness of the long wavelength UVA measurement.
Transmittance or blocking of erythemally weighted ultraviolet radiation through fabrics can be defined only in terms of a test method.
There is no independent method for determining the true value. Until such precision information is available, users of the method should use standard statistical techniques in making any comparison of test results aafcc betweenlaboratory averages.
However, because the satcc component does not contribute to the UPF, the spectral distribution of the source is irrelevant, so long as it provides sufficient energy to cover the spectral range of interest to acceptable signal to noise ratios in the spectral data. Record the individual measurements. The average UPF was