Sound Intensity Input Channel Selection

X/Y/Z Axis

  • Enable Axis
    Each of the 3 available directional axes can be turned on or off. At least one of them must remain enabled.
  • Mic Spacing
    The intensity probe will have its 2 microphones spaced a certain distance apart. This value should match the physical spacing of the microphones for accurate results.
  • Mic 1/2
    Any available input or output channel may be selected for Mic 1 and Mic 2. The probe should be oriented so that Mic 1 is the microphone closer to the acoustic source being measured and Mic 2 is further from it on the line the defines the axis of measurement. In other words, the axis is defined as the line passing through both microphones in the intensity probe, in the direction of mic 1 to mic 2.
  • Mic 2/1 Mag/Phase Correction
    Selecting this option opens a menu for loading and previewing frequency response data that can be used to apply a magnitude and phase correction to effectively match the 2 probe microphones in order to minimize errors in particle velocity and sound intensity measurements.
    The frequency response data used for correction can be obtained by measuring the response between the 2 microphones in the Dual FFT Analyzer tool. This can be done using an intensity calibrator into which both microphones are inserted, or by placing the probe in an anechoic chamber and exciting it with a loudspeaker.
    There is an option to load multiple frequency response measurements to create an average response for microphone correction. This means that the response between the mics could be measured with the probe placed so that it is pointed at the loudspeaker in an anechoic chamber and then the response could be measured again with the probe rotated by 180ยบ so that it points away from the speaker. The average of the two measurements should then be suitable for correction of the probe microphones for more accurate particle velocity and intensity measurements.