CCP Free-field Standard Microphone Set GRAS 1/4″ 46BE (4-80kHz)

Introduction

• Through a close cooperation with our customers, we know that data-safety is highly important because the costs related to unsuited and unreliable sensors may determine whether your project turns into a success or not.
• For our users, data safety translates directly into requests for easier microphone selection, simple system configuration and reduction of measurement errors.
• To meet these requirements, we invented the microphone set concept. It is simple, reliable and robust and consists of a microphone cartridge and preamplifier combination, which is calibrated as one unit. This eliminates errors because there is only one sensitivity value to account for and the risk of contaminating the interface is eliminated. Combine this with our unique and proven design and you have the most reliable measurement microphone sets available in the industry today.

Typical applications and use

• The 46BE is a free-field microphone set and as such optimized for all acoustic applications, where the location of the main sound source is known and the microphone can be pointed directly at it ensuring 0° incidence. However it should be noted that the small size of the 1/4″ microphone body and diaphragm also enables pressure and random-incidence (diffuse field) measurements up to 20 kHz without removing the protection grid or need for further compensation. This all-use feature is very useful if you are not able to point out the nature of your sound field.)
• The high cut-off frequency makes it ideal for ultra-sonic diagnostics and impulse measurements, where minimum distortion and high resolution are obtained by the small size and fast response of the diaphragm.
• Regarding temperature range, see the Specifications. Should higher temperature limits be required, we recommend considering  the GRAS probe microphones where the microphone and preamplifier can be isolated from the hot source.

Design

• The GRAS 46BE is a high-performance 1/4″ free-field standard microphone set for measuring high sound pressure levels at high frequencies. In our clean-room environment the set is assembled and sealed with a label. However, the microphone set can be dismounted, if  you wish to use the components separately.

Microphone

• The microphone cartridge is the high-quality IEC  61094 WS3F standardized GRAS 40BE 1/4″ Prepolarized Free-Field Microphone, designed for long-term reliability in multiple environments.
• The prepolarization is obtained through an electret that is inflicted on the microphone back-plate under highly controlled conditions. The electret is then charged to match the specified microphone sensitivity.

Preamplifier

• The preamplifier is the GRAS 26CB 1/4″ CCP Standard Preamplifier with Microdot connector, and based on our well-known circuit board substrates. In the industry these are famous for their low self-noise, wide frequency and excellent slew rate performance.

Compatibility

• To perform as specified the GRAS 46BE microphone set requires a constant current input module that can deliver 4 mA and 24 V unloaded CCP voltage supply. If the  constant current supply is lower, the capability of driving long cables is reduced and consequently the upper frequency is reduced. If the voltage supply is lower it will influence the upper dynamic range.
• The microphone set is terminated with a 10/32 UNC Microdot female connector. Ready to use coax cable assemblies of various types and lengths are available in standard as well as customized lengths.
• The 46BE is IEEE 1451.4 TEDS v. 1.0 compliant. If your measurement platform supports Transducer Electronic Data Sheets you will be able to read and write data like properties and calibration data.