The standard applies to boiler water and drinking water with a pH higher than 8.35. The water must not contain any components that consume acid other than HCO3~, C032" and 0H~ (see Appendix A).
NEN 6532-1986 history
1986NEN 6532-1986 Water - Titrimetric determination of the content of hydrogen carbonate, carbonate and hydroxide in water with a pH higher than 8,35