Test methodMET-000002

Silt density index test

SaveStandardizedScientifically reviewedLevel 3 · Monitoring, measurement & analytics

Method code: ASTM D4189
Principle: Time to filter 500 mL through a 0.45 µm membrane at 207 kPa (30 psi), at the start and after 15 minutes

measures

Parameter · PAR-000006Silt density indexAn index of the particulate fouling potential of RO feed water, from the rate at which a 0.45 µm filter plugs at constant pressure.Open

is governed by

Standard · STD-000002ASTM D4189 — Silt density index (SDI) of waterOpen

cites

Standard · STD-000002ASTM D4189 — Silt density index (SDI) of waterOpen

Version history

Version 1 · published 3 Nov 2026