Changes in temperature, humidity and atmospheric pressure MAY change microphone sensitivity. This is why environmental CONDITIONS are stated on PCB® calibration certificates. The sound field can also have a SIGNIFICANT effect on the measured sound pressure at frequencies above 5 KHZ. Be sure to use the correction curves that are specified for the sound field where the measurement is being performed. It is also noteworthy that these sound fields are often idealistic. In practice, a "free" field may not be complete free of reflections or a random incidence field may not provide reflections from all directions. The mounting configuration of the microphone and objects near the microphone can affect the measured response even when located behind the microphone. Every configuration is different. SIGNAL conditioning and data acquisition equipment can affect the sound measurement by limiting the dynamic range or attenuating the signal at different frequencies.

Changes in temperature, humidity and atmospheric pressure may change microphone sensitivity. This is why environmental conditions are stated on PCB® calibration certificates. The sound field can also have a significant effect on the measured sound pressure at frequencies above 5 kHz. Be sure to use the correction curves that are specified for the sound field where the measurement is being performed. It is also noteworthy that these sound fields are often idealistic. In practice, a "free" field may not be complete free of reflections or a random incidence field may not provide reflections from all directions. The mounting configuration of the microphone and objects near the microphone can affect the measured response even when located behind the microphone. Every configuration is different. Signal conditioning and data acquisition equipment can affect the sound measurement by limiting the dynamic range or attenuating the signal at different frequencies.