scope:

This standard gives the principles and recommended units of the Tax System for the expression of linear density and includes in Appendix A conversion tables for calculating the text values of number or counts in other systems together with in Appendix B a statement of the procedure for the implementation of the Tax System in trade and industry. The Tax System is applicable to all kinds of textile fibers, intermediate products (for example tops, slivers and rovings), yarns and similar structures. This part of ISO 15923 specifies methods for the automatic performance of spectrophotometric and turbid metric analyses with a discrete analysis system for determining ammonium, nitrate, nitrite, chloride, orthophosphate, sulfate, and silicate. The field of application is ground, potable surface, waste, elutes, and boiler water.