ME 120 Experimental Methods Laboratory6

ME 120 Experimental - ME 120 Experimental Methods Laboratory Ananda Mysore Spring 2008 Ananda Mysore Sound Pressure Measurements Objectives Become

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
ME 120 Experimental Methods Laboratory Spring 2008 Ananda Mysore Ananda Mysore
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Sound Pressure Measurements s Objectives s Become familiar with hardware and techniques to measure sound pressure s Measure Sound level of various size fan modules Spring 2008 ME 120 Experimental Methods Laboratory Ananda Mysore s Calculate S/N of acoustic measurements s Fan Noise = f(size & operating speed)
Background image of page 2
Basics s @ 20deg C Vel of sound = 344m/sec s Audible frequencies - 20 to 20000Hz s Bruel &Kjaer 2236 Precision Integrating sound level meter Spring 2008 ME 120 Experimental Methods Laboratory Ananda Mysore s Condenser Microphone S Thin metal foil stretched like drumhead over a frame. Pressure changes > diaphragm movement > changes in capacitance> milli-volt signal > pre amplifier > other amplifier stages > A/D converter b Free-field response Microphone > one direction only b Random-incidence Microphone > Equally from all directions
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Basics s SPL is a measurement of sound strength on a logarithmic scale s L = SPL = 10 log(Signal Power/Ref Power)
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/08/2010 for the course ME 120 at San Jose State University .

Page1 / 11

ME 120 Experimental - ME 120 Experimental Methods Laboratory Ananda Mysore Spring 2008 Ananda Mysore Sound Pressure Measurements Objectives Become

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online