For pistonphones

The GRAS OP0023 contains calibration adapters for 1/2”, 1/4" and 1/8” sizes of  GRAS Flush-mount Microphone Sets.

The GRAS OP0025 kit contains a calibration adapter for GRAS 1/4" precision Surface Microphones.

Coupler for 1” microphones. For use with GRAS pistonphones.

Two-port coupler for 1/2” microphones. Used in comparison calibrations between two 1/2” microphones; one of which is a reference microphone. It can also be used in measuring the P-I (Pressure-Intensity) Index of intensity probes at 250 Hz. For use with GRAS 42AA & 42AP Pistonphones.

Two-port high-pressure coupler for 1/2” microphones. Used in comparison calibrations between two 1/2” microphones; one of which is a reference microphone. It can also be used in measuring the P-I (Pressure-Intensity) Index of intensity probes at 250 Hz. For use with GRAS 42AC Pistonphone.

Pistonphone coupler which is factory mounted on GRAS Pistonphone and they are factory calibrated as one unit.

Adapter for GRAS  1/4" and 7 mm microphones when calibrating using GRAS Pistonphones and Sound Calibrator.

1/2" Adapter for 1/8" microphones when calibrating using GRAS pistonphones and Sound Calibrator.

Octopus couplers for calibrating up to eight 1/2" microphones simultaneously.

A larger-volume coupler for enabling GRAS 42AA/AP Pistonphone to produce a sound pressure level of 94 dB instead of 114 dB re. 20 μPa. Essential when calibrating highly sensitive, GRAS low noise measuring systems.

A pistonphone adapter for calibration checking the Ear Simulator Type 43AE when a pinna simulator is mounted on the IEC 60711 Ear Simulator RA0045.

Adapter for Pistonphone calibrating a GRAS RA0045 Ear Simulator with a KEMAR Ear Canal extension.

This precision barometer has an LCD which can display (toggle button) either the static-pressure correction (e.g. -0.13 dB) for a pistonphone or the ambient static pressure (e.g. 997 hPa). This product is intended as optional accessory for pistonphones which as standard has an analogue barometer included i.e. for GRAS 42AA, 42AC & 42AC-S2. When used for correction of these, the accuracy is improved.

This is a pistonphone adapter for sensitivity calibration of our precision 1/4" surface microphone sets. The adapter is designed for laboratory calibration and can also be used for in-situ verification.

This is a pistonphone adapter which is designed for field verification of the 1/2" flush-mount microphone included in GRAS 67AX/67AD Ground Array Microphone kits.