standard silica scale
standard cobalt scale
standard platinum scale
platinum cobalt scale
10 ppm
20 ppm
30 ppm
50 ppm
starch iodide method
orthotolidine method
both starch iodide method and orthotolidine method
none of the above
dissolved oxygen
residual chlorine
biochemical oxygen demand
dose of coagulant
total alkalinity
total hardness
total hardness - total alkalinity
non carbonate hardness