For pistonphones

The GRAS OP0023 contains calibration adapters for 1/2”, 1/4" and 1/8” sizes of  GRAS Flush-mount Microphone Sets. These adapters are designed exclusively for sensitivity calibration of the GRAS 47AX, 47AD, 47BX, and 47DX microphones using a GRAS pistonphone, such as the 42AP. They are not compatible with the GRAS 42AG sound calibrator.

The GRAS OP0025 kit contains a calibration adapter for GRAS 1/4" precision Surface Microphones. The GRAS OP0025 kit includes the RA0202 sensitivity calibration adapter, designed specifically for GRAS 40LA and 40LS 1/4" surface microphones. This adapter is compatible exclusively with GRAS pistonphones, such as the 42AP.  

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. This pistonphone coupler is designed exclusively for calibrating low-noise microphones, such as the GRAS 40HF, 40HH, 40HL, 40HT, and 47HC. It is not suitable for use with low-noise ear simulators, including the GRAS 43BB product family. Alternatively, the GRAS 42AG sound calibrator set at 94 dB can be used to calibrate both low-noise ear simulators and microphones.

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