BS ISO 3858:2018 pdf free

BS ISO 3858:2018 pdf free.Rubber compounding ingredients – Carbon black
This document specifies a method for the determination of the light transmittance of the toluene extract from carbon black for use in the rubber industry, as a means of measuring the discolouration caused by the extractable matter.
The light transmittance value provides an estimate of the degree of discolouration caused by the toluene-extractable matter present on the surface of the carbon black.
This method might not be applicable to carbon blacks with a high extractable-matter content.
Spectrophotometer, with a tungsten filament lamp, 20 nm maximum spectral passband width,capable of measuring percent transmittance at a wavelength of 425 nm. The instrument shall be of the high-resolution prism or grating type, eliminating the use of an optical filter. The instrument shall be operated in accordance with the manufacturer’s operating manual for optimum performance. Some instruments might require the use of a constant-voltage transformer in the electricity circuit in order to compensate for voltage variations of more than 4 V.
NOTE Current types of photometer could be used. However, they might differ in passband width from the specified one, and they might give different transmittance results. Proper calibration of such instruments over the whole transmittance range against a high-resolution spectrophotometer (of a passband width of 2 nm at 425 nm, for example) might be performed for possible corrections of the readings.
Fill the cell with filtered toluene and wipe the outside surfaces thoroughly with wiping paper or optical lens tissue (6.10), while holding the cell in front of a suitable light source for proper inspection.
The contents of the cell shall be free of any contaminant, such as lint particles, which might cause light scattering and influence the results. If necessary, clean the inside surface with a cotton swab (6.11), or wipe again the outside until perfectly clean. If cleaning of the internal cell surface is necessary, restart the procedure as in 9.1.5.
Place the absorption cell in the spectrophotometer, and adjust the instrument to read 100 % transmittance at a wavelength of 425 nm.BS ISO 3858 pdf download.