Questions_and_Answers_2__for_H92222-17-R-0011.pdf

Questions and Answers for H92222-17-R-0011 SURG As of 15 Feb 17

Below Question is from the original Questions and Answers

165. Orientation of the microphones during sound pressure level testing? a. The new microphones purchased for use on SURG 2.0 testing (4944A Delta Tron Pressure Field .25" Mic, 1.00V/Pa) mics are pressure field type mics and are designed to be pointed directly at the sound source. Based on the weapon platform and for consistency across each vendor the mics will be pointed at the muzzle of the weapon during any sound pressure level measurements. Please note that this was incorrectly demonstrated at SURG industry day at NSWC Crane. The microphone should have been aimed at the muzzle of the MK18 MOD1 used for demonstration

The UPDATED INFORMATION TO THE ABOVE QUESTION AS OF 15 FEBRUARY 2017

Q165 UPDATED: Orientation of the microphones during sound pressure level testing?

A165 UPDATED: The new microphones purchased for use on SURG 2.0 testing (4944A Delta Tron Pressure Field .25" Mic, 1.00V/Pa) microphones are pressure field type microphones and are designed to be pointed directly at the sound source.

That said the design of the test is to replicate the human ear (shooters ear position). To best replicate the analog of the human ear a pressure field microphone needs to be orientated perpendicular to the source of sound. To ensure that the orientation is consistently 90° to the source, the microphone will be positioned such that the major axis of the microphone is normal (90°) to the ground with the mic end pointed upwards.