Product Catalogue Measurement Microphones Q1-2020

We Make Microphones GRAS is a worldwide leader in the sound and vibration industry. We develop and manufacture state-of-theart measurement microphones and related equipment to industries where acoustic measuring accuracy and repeatability is of utmost importance. This includes applications and solutions for customers within the fields of aerospace, automotive, audiology, consumer electronics, and other high-demanding industries. Unique Repair Service As a family-owned company, we safeguard our heritage by constantly striving to push the boundaries of what is possible and help our customers improve...

LEMO Microphone Sets

Microphone Selection Microphone Sets and Microphones Special Microphones Low-noise Measuring Systems Intensity Probes

Pistonhones and Calibration Equipment Artificial Ears, Ear and Mouth Simulators, and KEMAR Power Modules

MICROPHONE SELECTION Choosing a Microphone Measurement microphones are available in many types covering various frequency ranges, dynamic ranges and application situations. The following guide is provided to help select the right microphone for a given application. Selecting a microphone involves a number of choices, which can be summarized as: Externally polarized vs. prepolarized Free-field, Pressure or Random incidence Dynamic range Frequency range Externally Polarized vs. Prepolarized All GRAS measurement microphones are of the condenser type. This requires a polarization voltage which can...

Free-field, Pressure or Random Incidence Measurement microphones can be divided into three groups: Free-field, Pressure, and Random incidence. The differences between microphones from group to group are at the higher frequencies, where the size of a microphone becomes comparable with the wavelengths of the sound being measured. Free-field Microphones A free-field microphone is designed essentially to measure the sound pressure as it was before the microphone was introduced into the sound field. At higher frequencies, the presence of the microphone itself in the sound field will disturb the sound...

MICROPHONE SELECTION Dynamic Range of a Microphone The dynamic range of a microphone can be defined as the range between the lowest level and the highest level that the microphone can handle. This is not only a function of the microphone alone but also of the preamplifier used with the microphone. The dynamic range of a microphone is, to a large extent, directly linked to its sensitivity. In general, a microphone with high sensitivity will be able to measure very low levels, but not very high levels, and a microphone with low sensitivity will be able to measure very high levels, but not very...

Frequency Range of a Microphone The frequency range of a microphone is defined as the interval between its upper limiting frequency and its lower limiting frequency. With today’s microphones, it is possible to cover a frequency range starting from around 1 Hz and reaching up to 140 kHz. Low-frequency measurements require a microphone with a well-controlled static pressure equalization with a very slow venting. Special versions are available for infra-sound measurements. High-frequency measurements are very sensitive to diaphragm stiffness, damping and mass as well as diffraction. Upper Limiting...

Microphone Sets Microphone Sets – a Safe and Easy Solution Daily situations where you mix up externally polarized and prepolarized microphones and preamplifiers or use wrong calibration data in your system setup are time-consuming and often not discovered until a whole set of measurement data is analyzed and consequently discarded. To help you avoid this we offer most of our measurement microphones as microphone sets: Pre-assembled and ready-to-use combinations of microphones and preamplifiers. Pre-assembled Sets The GRAS 46XX-series of pre-assembled microphones and preamplifiers offers carefully...

Microphone Sets

LEMO MICROPHONE SETS FREE-FIELD AND RANDOM INCIDENCE 1/2” LEMO Free-field Standard Microphone Set, Wide Frequency 1/4” LEMO Free-field Standard Microphone Set 46AC is a high-performance 1/2” free-field standard microphone set for measuring medium sound pressure levels at high frequencies; with built-in TEDS and 7-pin LEMO connector. 46BF-1 is a 1/4” high frequency free-field microphone set for high level measurements with built-in TEDS and a 5-pin LEMO connector. To be used with AA0091 or AA0092-CL 5-pin to 7-pin LEMO cable. 1/2” LEMO Free-field Standard Microphone Set 1/2” LEMO Random incidence...

1/2” LEMO Pressure Standard Microphone Set 1/4” LEMO Pressure Standard Microphone Set 46AG is a 1/2” high precision pressure microphone set for laboratory work and coupler measurements with built-in TEDS and 5-pin LEMO connector. To be used with AA0091 or AA0092-CL 5-pin to 7-pin LEMO cable. A front-vented version is available, 46AG-FV. 46BP-1 is a 1/4” LEMO microphone set for pressure measurements for measuring high sound pressure levels at high frequencies, with a 5-pin LEMO connector. To be used with AA0091 or AA0092-CL 5-pin to 7-pin LEMO cable. 1/2” LEMO Pressure Standard Microphone Set,...

CCP MICROPHONE SETS FREE-FIELD, RANDOM INCIDENCE AND PRESSURE CCP Rugged Pressure Microphone 146AE is a versatile 1/2” free-field measurement microphone set for the broadest range of noise measurements in challenging environments. It is well protected against vibrations, humidity, dust, oil mists, and temperatures from -40 to 125°C. A comprehensive range of accessories is available, visit www.gras.dk. 147AX is a surface mounted pressure microphone. It comes with a novel magnetic mounting system which provides precise, repeatable and easy mounting. It is well protected against vibrations, humidity,...

1/2” CCP Pressure Standard Microphone Set 1/4” CCP Pressure Standard Microphone Set, High Pressure 46AO is a 1/2” pressure high precision microphone set for laboratory work. Including built-in TEDS and BNC connector. A front-vented version is available, 46AO-FV. 46BG is a 1/4” microphone set for high level measurement with built-in TEDS and a Microdot connector. Its low sensitivity and special-designed diaphragm make it ideal for handling high levels. A front-vented version is available, 46BG-FV. 1/2” CCP Pressure Standard Microphone Set, High Sensitivity 1/4” CCP Pressure Microphone Set, High...