G.R.A.S. 40DP 1/8" Ext. Polarized Pressure Microphone Date 10-06-2013. Page 1 of 5 G.R.A.S. 40DP 1/8" Ext. Polarized Pressure Microphone Sensitivity: 1 mV/Pa Freq resp: 6.5 Hz to 140 kHz Dynamic range: 40 dBA to 178 dB The 40DP is an IEC 61094 1/8" externally polarized pressure microphone with rear-venting. Due to its tiny size, this high-precision Type 1 condenser microphone can be used to measure very high frequency sounds without disturbing the sound field. Introduction The 40DP is an IEC 61094 1/8” externally polarized pressure microphone with rear-venting. Read about the prepolarized equivalent.[40DD] It is a high-precision Type 1 condenser microphone made according to IEC 61094-4 requirements. Due to its tiny size, it can be used to measure very high frequency sounds without disturbing the sound field. It can measure sound pressure levels up to 174 dB in the range of 6.5 Hz to 140 kHz. 40DP is individually factory-calibrated and delivered with a calibration chart stating its specific open-circuit sensitivity and pressure frequency response.

G.R.A.S. 40DP 1/8" Ext. Polarized Pressure Microphone Date 10-06-2013. Page 2 of 5 The 40DP has a low sensitivity making it perfect for sound measurements at high frequencies and very high level pressure. The low sensitivity, together with the wide frequency response, makes the 40DP very suitable for impulse noises. The 40DP can be used for making acoustic measurements in laminar airflow by mounting the RA0173 1/8” Nosecone in place of the microphone grid. The nosecone tip should be point upstream in a laminar flow to reduce the turbulence created by the microphone itself in the airflow. Compatibility...

G.R.A.S. 40DP 1/8" Ext. Polarized Pressure Microphone Date 10-06-2013. Page 3 of 5 Depending on the use, measurement environment, and internal quality control programs, we recommend recalibrating the microphone at least once a year. Learn more about G.R.A.S.' calibration services. Specification Open-circuit sensitivity @ 250 Hz (±2 dB) Resonance frequency Dynamic range lower limit (microphone thermal noise) Dynamic range upper limit Dynamic lower limit with G.R.A.S. preamplifier Dynamic range upper limit with G.R.A.S. preamplifier @ ±14 V / +28 V power supply Dynamic range upper limit with G.R.A.S....

G.R.A.S. 40DP 1/8" Ext. Polarized Pressure Microphone Date 10-06-2013. Page 4 of 5 Influence of axial vibration @1 m/s² CE/RoHS compliant, WEEE registered Weight

G.R.A.S. 40DP 1/8" Ext. Polarized Pressure Microphone Date 10-06-2013. Page 5 of 5 Tradition Since the establishment in 1994, G.R.A.S. have been 100% dedicated to developing and manufacturing high-quality measurement microphones and related acoustic equipment. Founded by the Danish acoustics pioneer Gunnar Rasmussen who for more than 60 years has contributed to the world of sound and vibration with his unique ideas and designs. From the first reproducible 1” condenser measurement microphone that enabled quality measurements and instrumentation for acoustic calibration, Mr. Rasmussen’s ingenuity...