This document describes the procedure for determining the air content in fresh concrete using an air entrainment meter. Key points: - An air entrainment meter is used to introduce water and apply air pressure to a concrete sample to measure its air content percentage. - The procedure involves filling and compacting the concrete sample, sealing it in the meter, pressurizing the chamber, and noting the stabilized air content reading on the pressure gauge. - The meter must be calibrated by removing a percentage of water from the container (5-10% depending on container size) and verifying the pressure reading corresponds to the expected air percentage.