G.R.A.S. Sound & Vibration AS, Denmark are manufacturers of Microphones, Hemisphere Structure for Sound Power Measurements, Intensity Probe, Calibration Equipment and Acoustic Test Fixtures, Head & Torso Simulators for Audiology Industry.
Calibration is an essential step in every precision measurement. G.R.A.S. offer s a wide range of equipment ranging from Hand-held calibrators, Pistonphone up to Phase calibrator & low frequency calibrator and Microphone calibration System and Audiometer Calibration system.
Hand-held Calibrator & Pistonphone:
Calibration Equipment (Phase Calibrator & Low frequency calibrator):
Calibration Systems (Audiometer Calibration System & Microphone Calibration System):
90AA Audiometer Calibration System: Level, frequency & distortion
90CA-S2 Microphone calibration System: Level (250 Hz, 114 dB) & Frequency (200 Hz-92 KHz) calibration
Also Electro static actuators and Power Module are available from M/s. G.R.A.S.
Technical Note: Periodic Verification of Microphones