Blaine Air Permeability Apparatus

The Blaine Air Permeability Apparatus is a standard testing instrument used to determine the fineness of Portland cement, pozzolanas, lime, and other finely pulverized materials. Expressed as specific surface area in square centimeters per gram or square meters per kilogram, this measurement provides vital insight into hydration kinetics, setting characteristics, and early strength development in cementitious binders.

The apparatus operates by measuring the time required for a fixed volume of air to pass through a compacted bed of powder with defined porosity. The assembly consists of a rigid support stand carrying a precision-calibrated glass U-tube manometer with an aspirator bulb, alongside a machined stainless steel or brass permeability cell fitted with a perforated disc, plunger, and filter paper discs to ensure standardized sample compaction and repeatable airflow dynamics.