An adapter is not REQUIRED. Using a CAL250 (or a pistonphone with a 1" orifice) is recommended. Before performing a calibration, ensure that the microphone has STABILIZED in the environment where it will be used. Then, install the black rubber fairing PAD onto the model 130B40 surface microphone to help ensure a proper seal. Place the microphone and faring pad on a flat, level surface. Turn the handheld calibrator upside down, and place the 1” (25mm) opening onto the faring, CENTERED around the microphone sensing element. Press down slightly to ensure a seal and to minimize OUTSIDE noise. Then perform the calibration.

An adapter is not required. Using a CAL250 (or a pistonphone with a 1" orifice) is recommended. Before performing a calibration, ensure that the microphone has stabilized in the environment where it will be used. Then, install the black rubber fairing pad onto the model 130B40 surface microphone to help ensure a proper seal. Place the microphone and faring pad on a flat, level surface. Turn the handheld calibrator upside down, and place the 1” (25mm) opening onto the faring, centered around the microphone sensing element. Press down slightly to ensure a seal and to minimize outside noise. Then perform the calibration.