Experimental water contains two types of contaminants, inorganic salts and dissolved organics, which are known to affect most laboratory experiments and therefore it is important that they be monitored. online monitoring in laboratory water systems. Standards define different laboratory water grades for both technical and economic reasons. The purpose of these norms is to ensure that the right water quality is used for a particular application, while limiting laboratory operating costs. Type 1 clean water is more expensive to produce than grade 2 or grade 3 water.