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:
Reference calibration Source
42AA: 114 dB, 250 Hz, Class 1
42AC: 134 dB, 250 Hz, Class 1
42AP: 114 dB, 250 Hz; Class 0
42AG: 250 & 100 Hz, 114 dB & 94 dB
Calibration Equipment (Phase Calibrator & Low frequency calibrator):
51AB: Intensity calibrator (for calibrating phase response of a pair of microphones used for measuring sound Intensity.
42AE: Calibration of microphones between the frequency as low as 0.1 Hz – 50 Hz
Calibration Systems (Audiometer Calibration System & Microphone Calibration System):