Acoustic Calibration Solutions from M/s. G.R.A.S. Sound & Vibration AS, Denmark.

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

Field Use:
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):

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