7.02 acoustic equivalent volume. Alternate method of stating acoustic compliance. Acoustic equivalent volume Va may be expressed as:
Va = γ po Ca = ρo c2 Ca
where γ is the ratio of specific heat at constant pressure for air to the specific heat at constant volume, 1.400 at sea level; po is ambient pressure in pascals, which, on a standard day at sea level, is 101,325 Pa; Ca is acoustic compliance in m3/Pa; ρo is density of air, 1.225 kg/m3 on a standard day at sea level; and c is speed of sound, 340 m/s on a standard day in air with a temperature of 15° C. Unit, cubic meter (m3).
Annotation Measurement of equivalent volume may involve both adiabatic and isothermal processes. For an isothermal process the ratio of specific heats is unity.« Back to Standards Terminolgy Index