Relationship between water qualities and treatments in the ultra pure water production system Available to Purchase

In an ultra pure water (UPW) production system which can satisfy the water qualities for 4 megabit DRAM, the changes in water qualities from a tap water (58.4 mg/dm³ as CaCO₃ hardness) as a raw water to UPW were followed from the view of the micro-structure and microdynamic behavior of water molecules with increasing of the water purity by a complex permittivity and ¹⁷O-NMR measurements, as well as measurements of resistivity, density, and so on. The dielectric relaxation time and spin-lattice relaxation time of ¹⁷O nuclei related to the microdynamic behavior of water molecules indicated a trace change between the tap water and UPW. However, the dielectric parameter α which characterizes a symmetric distribution of relaxation times was gradually lowered with increasing of the water purity. The relationship between the half-width of ¹⁷O magnetic resonance and pH gave the rate constants for the prototropic charge migration in water. The difference of α and density between the tap water and UPW became a measure of water purity.