Description

The silt density index test is performed using a .45 micron, 47mm diameter filter. The water to be tested is supplied to the filter at a constant pressure of 30 psi. The test involves measuring the time it takes to collect a 500 ml sample through the filter at the start of the test and comparing it with the time it takes to collect a 500ml sample after water has flowed through the filter (at 30psi) for 15 minutes. The sample times are applied to the formula below to obtain the SDI15 value