1/2“自由场传声器，外部极化
专为高精度测量设计的自由场传声器，需要高灵敏度，频率响应范围为 3 Hz 至 20 kHz。
4190 型
4190-L-001型专为需要高灵敏度传声器的场合设计，用于高精度自由场测量。
| Standard | IEC 61672 |
| Sound field | Free field |
| Polarization voltage | 200V |
| Sensitivity | 50 mV/Pa |
| Lower limiting frequency | 3.15 Hz |
| Higher limiting frequency | 20 kHz |
| Inherent noise | 14.6 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 higher frequencies, reflections and diffractions cause a pressure increase in front of the diaphragm of a microphone. If not corrected for this would result in an increased output voltage.
A free-field optimisation means that the frequency response of the microphone has been designed in such a way that the free-field response at 0 degrees incidence is flat. This microphone is optimised for use with the protection grid in place.
Free-field microphones are commonly used for sound measurement in an anechoic chamber or far away from reflecting buildings, etc. Another area for free-field microphones is for general electroacoustic measurements like loudspeaker and microphone measurements.
Type 4190 is not only suited for use in class 1 Sound Level Meters but also for all high-precision acoustic measurements where a robust and stable, externally polarized free-field microphone with an upper frequency of 20 kHz is required.
A press-fitted, stainless-steel diaphragm ensures superior long-term stability and mechanical robustness – Type 4190 will withstand the 1 m drop test of IEC 60068-2-32.
Type 4190 requires an external polarization voltage and must therefore be used with a classical preamplifier. Externally polarized microphones may be used at higher temperatures without severe changes in sensitivity.
Type 4190 is available in TEDS combinations with the classical Microphone Preamplifier Type 2669. The TEDS microphone is considered one unit and has been sealed in a clean environment.
The TEDS is programmed with the loaded sensitivity of the actual cartridge and the data is therefore readily available. The default TEDS template is to IEEE P 1451.4 but TEDS to IEEE 1451.4 is available on request.
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.