There are a number of models and choices when deciding to purchase a microphone and preamplifier system to measure sound or unwanted sound, called noise. In some cases, multiple microphone and preamplifier models could be used for the same application. Download the PCB Microphone Handbook for detailed information concerning microphone selection, maintenance, calibration and more.

Factors that influence microphone selection

  1. Assess sensors owned (acoustic, accels, pressure), power supplies & cables
  2. Environment for testing

    • Indoors or outdoors
    • Duration of test
    • Background noise, and frequencies of background noise
    • Humidity of the test area
    • Temperature in test area

  3. Test object location and sensor positioning
    • Location of the test object
    • Location and positioning of the sensor relative to test object
    • Characteristics of surrounding objects
    • Proximity of surrounding objects to the sensor and to the object to be tested

  4. Minimum and maximum frequency and amplitudes required
  5. Preference for prepolarized or externally polarized microphones
  6. Your budget for microphones and the cost per channel of the system

There are three types of sound fields that influence microphone selection

Free Field:

  • No reflections
  • The primary direction of the sound source and the axis of the microphone are collinear

Pressure:

  • Flush mounted inside a duct or acoustic coupler
  • Similar to pressure transducer

Random Incident/Diffuse:

  • Reflections
  • Multiple sources are transmitting in multiple locations

 

Microphone Comparison