Accession Number : ADA320703

Title :   Sound Exposure Caused by the Automatic Rifle Diemaco C7A1 and the Mortar 60 mm Hotchkiss-Brandt (Geluidbelasting veroorzaakt door het geweer diemaco C7A1 en het mortier 60 mm Hotchkiss-Brandt).

Descriptive Note : Final rept.,

Corporate Author : METAALINSTITUUT TNO APELDOORN (NETHERLANDS)

Personal Author(s) : Bronkhorst, A. W.

PDF Url : ADA320703

Report Date : 14 NOV 1996

Pagination or Media Count : 26

Abstract : Sound measurements were conducted for the Diemaco C7A1 automatic rifle and the mortar 60mm Hotchkiss-Brandt in order to evaluate the sound exposure caused by these weapons. Measurements were performed at the ears of the gunner (or loader) and at various positions in the free field around the weapon. For the Diemaco, the gunner could be either standing or lying on the ground and the microphone was placed at heights corresponding to these positions. The results show that this factor has some effect on the peak levels around the weapon, but not on the impulse duration (tau(sub-10)) or on the peak levels at the ears of the gunner. The average peak level and duration at the ears were 153 dB SPL and 3.2 ms, respectively. Around the weapon, maximum peak levels were somewhat higher but the durations were shorter. Two loads were used during the measurements for the 60mm mortar: 0 and 2. At the ear of the gunner or loader, peak level and duration for the largest load were 163 dB SPL and 9.7 ms, respectively. Around the weapon, lower values for both peak level and duration were found. When the smaller load was used, peak levels decreased by 5 to 10 dB and the duration was halved. For both weapons, it was investigated whether calculation of the impulse duration based on either (linear) impulse or sound exposure level yielded the same results as direct determination from the waveform. The best correspondence was obtained for durations that were calculated using the impulse level.

Descriptors :   *MACHINE GUNS, *ACOUSTIC MEASUREMENT, *MORTARS, NETHERLANDS, IMPULSE NOISE, RIFLES, SOUND PRESSURE, DUTCH LANGUAGE, GUNNERS.

Subject Categories : Guns
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE