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