TOP-1-2-608A, TEST OPERATIONS PROCEDURE: SOUND LEVEL MEASUREMENTS (01-JAN-2011)

TOP-1-2-608A, TEST OPERATIONS PROCEDURE: SOUND LEVEL MEASUREMENTS (01-JAN-2011)., This Test Operations Procedure (TOP) describes procedures for measuring the sound levels transmitted through air of developmental and production materiel as a means of evaluating personnel safety, speech intelligibility, security from acoustic detection and recognition, and community annoyance. It covers tests for steady-state noise from military vehicles and general equipment, and impulse noise from weapon systems and explosive-ordnance materiel. For materiel that produces sound-pressure levels 171 decibels (dB) (6.89 kilopascal (kPa) or 1.0 pounds per square inch (psi)) and above, the procedures and instrumentation described in International Test Operations Procedure (ITOP) 04-2-8221, for measuring blast overpressure, apply. This TOP does not include procedures for measuring the noise from aircraft. Per Military Handbook (MIL-HDBK)-1908B2, steady-state noise is defined as a periodic or random variation in atmospheric pressure at audible frequencies. It may be continuous, intermittent, or fluctuating, with the sound-pressure level varying over a wide range, provided such variations have a duration exceeding one second.