water grades

The ISO standard 3696 defines 3 different grades of water:

Parameter	Grade 1	Grade 2	Grade 3
Conductivity μS/cm (Temp Corrected)	<0..1	<1.0	<5.0
pH at 25 ̊C	N/A	N/A	5.0-7.0
Oxidizable matter Oxygen (O2) content mg/L	N/A	<0.08	<0.4
Absorbance at 254 nm and 1 cm optical path length, absorbance units	<0.001	<0.01	N/A
Residue after evaporation on heating at 110 ̊C mg/kg	N/A	<1	<2
Silica (SiO2) mg/L	<0.01	<0.02	N/A

DiaSys water purifiers are able to produce water of Grade 2.

DiaSys Water Purifier Systems