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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The limits of the spectral range of ultraviolet radiation are not well defined and may vary according to the user.
Note, some samples may not be capable of achieving the specified wet pick-up such as tightly woven synthetic fabrics. 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 wavelength calibration of a spectrophotometer can be performed using the absorption spectra of a holmium oxide glass filter.
Avoid evaporative reduction of the moisture content below the specified level before the actual UV transmission measurements are made. Instrument Verification and Calibration 5. As a means of estimating this property, the method has no known bias. Principle ance transmitted and calculated through air to the average effective UV-R irradiance transmitted and calculated through fabric.
The use of physical standards are recommended for validating the measurement of spectral transmittance. 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 decrease in transmission of the filter with increasing wavelength may reduce the usefulness of the long wavelength UVA measurement. The contribution of stray radiation within the instrument, including that due aatcc sample fluorescence, shall produce an error of less than 0. However, the techniques for stretching the specimens are not part of this method and are addressed in a aarcc test procedure. Illumination and viewing geometries.
There is no independent method for determining the true value. The cross-sectional area of the illuminating beam shall be at least 10 times the dimension of the largest hole in the test material. Allow the specimen to remain submerged for 30 minutes. In Marchan ul- A1. The precautions are ancillary to the testing procedures and are not intended to be all inclusive.
The error due to the fluorescence can be removed by placing a UV transmitting, visible blocking filter after the sample. The intervals in Table II are in 2 nm.
A Schott Glass UG11 filter has been found to be satisfactory. The effects of fluorescence are, therefore, eliminated at most UVR wavelengths.
UV STANDARD | Measuring methods
Calibrate the spectrophotometer or spectroradiometer according to manufacturer instructions. Aactc, because the fluorescent 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.
Validate the linearity of the transmittance scale by aatcd of either calibrated neutral density filters or calibrated perforated screens supplied by the instrument manufacturer or standardizing laboratories. The reference beam impinges on either a portion of the sphere wall or a reference material mounted at a diametrically opposed port opening.
The average UPF was 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 satcc long wavelength UVA measurement. In this geometry the specimen is illuminated by an internally illuminated integrating sphere.
aatcx The integrating sphere surface is internally coated or constructed using a material that is both diffuse and highly reflecting in the ultraviolet region. Record the individual measurements. Until such precision information is available, users of the method should use standard statistical techniques in making any comparison of test results for betweenlaboratory averages. Filter, Schott Glass UG11 see Avoid aqtcc the specimen during preparation and handling.
The specimen is viewed unidirectionally with an axis not greater than 0. 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.
AATCC Launches New Tools for Testing UV-Protective Fabrics
Between-laboratory precision has not been established for this test method. Prepare only one specimen zatcc a time. This includes nearly all wavelengths in the UVR spectral region. The error can be eliminated in either geometry by use of a separate reference beam that traverses its own port opening in the sphere. 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.
Appendix A Spectrophotometer or Spectroradiometer Specifications The measured wavelength interval over this spectral range should not be greater than 5 nm. It must be noted that stretching the specimens could change the UPF properties. Transmittance or blocking of erythemally weighted ultraviolet radiation through fabrics can be defined only in terms of a test method.
The intervals in Table I are in 2 nm. In spectrophotometers and spectroradiometers where the illumination is polychromatic and the monochromator follows the specimen satcc the optical path, the artificially high values of transmittance appear at the emission wavelengths of the fluorescing agent. Precision and Bias If the fabric has low moisture absorption, repeat the soaking and wringing steps.
Although integration is indicated from nm to the stated wavelengths, little or no contribution will occur in the nm region. Apparatus and Materials 8. Press and move the specimen from time to time to ensure a good and uniform penetration. Calibrate the wavelength scale of the spectrophotometer or spectroradiometer using the spectral aatcc lines of an electrical discharge in mercury vapor. Uses and Limitations 3. These safety precautions are for information purposes only.