Jar test is a pilot-scale laboratory test that simulates coagulation or flocculation with differing chemical doses. The purpose of the jar test is to estimate the minimum coagulant dose required to achieve certain water quality goals. Jar tests are conducted on a four- or six-place gang stirrer, which can be utilized to simulate mixing and settling conditions in a clarifier.
Jar test helps to determine the right amount of treatment chemicals: the lowest dose of chemicals that provides satisfactory settling is the dose used to treat the water.