8 CY of nominal 4000 psi, air‐entrained (6%) concrete were batched from a stationary mixer into an Oshkosh front‐discharge ready‐mix truck with an 11 CY drum, fitted with a CiDRA, “SMARThatch” acoustic air meter. The truck arrived at the test‐site 20 minutes after batching. Concrete was sampled four times over 95 minutes on‐site per ASTM C172, with two intermediate discharges of concrete into forms, and two additions of water. At each sampling, ASTM C231 (pressure‐meter) and C138 (gravimetric) air tests were conducted by ACI‐certified technicians, and 4x8 cylinders were cast for compression‐strength and hardened‐air analysis per ASTM C457. All test equipment was calibrated immediately prior to test. Acoustic air content was monitored continuously throughout the experiment for comparison with results of currently accepted, standard methods. All results are compiled in the graph and briefly discussed below.