What does SDI mean in practice?
The test measures the rate of decline in flow through a 0.45 µm membrane at constant pressure over a fixed time interval.
When does it matter?
SDI assesses the partial fouling potential of RO feed but does not predict full scale mineral fouling or biofouling.
Which solutions are related to it?
The result is used to evaluate prefiltration and trend, maintaining the same procedure, pressure and test time.