1/2“次声传声器，预极化
次声传声器专为高精度、高灵敏度声学测量而设计，频率范围为0.02 Hz至20 kHz。
4964 型
次声传声器4964型专为需要高灵敏度次声传声器的场合设计，用于高精度声学测量。4964型预极化传声器可与CCLD和经典前置放大器一起使用，特别适合用于电池供电设备和在高湿度环境中操作。
| Standard | IEC 61094 |
| Sound field | Free field |
| Polarization voltage | 0V |
| Sensitivity | 50 mV/Pa |
| Lower limiting frequency | 0.02 Hz |
| Higher limiting frequency | 20 kHz |
| Inherent noise | 14.2 dB(A) |
| Upper limiting of dynamic range | 146 dB |
| Diameter | 1/2 inch |
| Venting | Rear |
| Minimum Temperature | -30 °C |
| Maximum Temperature | 150 °C |
| Minimum Temperature | -22 °F |
| Maximum Temperature | 302 °F |
At infrasound and frequencies below a few kHz, the pressure and free-field response are the same. At higher frequencies, reflections and diffractions cause pressure to increase in front of a microphone's diaphragm.
Type 4964 has been optimized for free-field, and designed for use with the protection grid in place. Type 4964 is also suited for use in class 1 sound level meters and for all high-precision acoustic measurements where a robust and stable free-field microphone with an upper frequency of 20 kHz is required.
A press-fitted, stainless-steel diaphragm ensures superior longterm stability and mechanical robustness – Type 4964 will withstand the 1 m drop test of IEC 60068–2–32.
As all Brüel & Kjær microphones, each Type 4964 is provided with an individual calibration chart including information about the open-circuit sensitivity, the frequency response in a free field as well as the electrostatic actuator response. Using the calibration data and the REq-X feature of LAN-XI, a real-time correction for different measurement situations can increase accuracy.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.