SOLIDS: Solids occurs in water either in solution or in suspension. These 2 types of solid are distinguish by passing the water sample through a glass-fibre filter. By definition, the Suspended Solid are retain on top of the filter and the Dissolved Solid pass through the filter with the water.
If the filtered portion of the water sample is placed in a small dish and then evaporated, the solid in the water remain as a residue in the evaporating dish. This material is usually called Total Dissolved Solid TDS. The concentration of TDS is expressed in term of mg/L. it can be calculated as follows.
Where A = equal to weigh of dish plus residue. Mg
B = Weight of empty dish
C = Volume of sample filtered mL.