The new Microtech Gefell MMS 212 1/2" measurement microphone was designed to be very insensitive to extreme temperatures (-40 °C to +125 °C), moisture, dust and vibration and is therefore ideal for measurement applications in very aggressive environments. The extended frequency range of the free field response, from 3,5Hz to 20kHz, combines with a 50 mV/Pa sensitivity, 15dBA of inherent noise, and tolerates SPL peaks up to 139 dB (136 dB RMS) for 3% THD at 1 kHz.
According to the company, this robustness is achieved by a special design of the protection grid, pressure compensation opening and BNC plug connector with Integrated Electronics Piezo-Electric (IEPE) power supply. The MMS 212 is an IP67 rated solution and can be calibrated with a standard 1/2" sound calibrator, offering TEDS for increased accuracy. An integrated power-on indicator in the MMS 212 permanently indicates that the microphone is working as intended, and helps to ensure reliable measurements in unique, sometimes unrepeatable situations.
Of course, there are many measurement situations where the actual sounds are extremely low, which requires a totally different measurement microphone. And that's why Microtech Gefell designed the new MMS 214 model, offering a particularly low inherent noise level, which enables acoustic measurements of very low sound pressure levels.
The MMS 214 uses an externally polarized capacitive pressure transducer that is able to capture a frequency range from 10 Hz to 16 kHz (±2 dB) or 5 Hz to 20 kHz (± 3dB) in free field response , with a sensitivity of 320 mV/Pa. The electrical connection uses BNC cables to connect measuring channels with an IEPE supply. The polarization voltage for the microphone capsule is generated in the combined microphone preamplifier, and the microphone is equipped with a built-in memory for TEDS identification and calibration according to IEEE 1451.
Both new measurement microphones are complemented with an extended range of accessories offered by Microtech Gefell, from simple adaptors, cables and windscreens, all the way to specialized supports and conditioning modules.
New MV 240 Preamplifier
Extending the vast catalog of Microtech Gefell's preamplifiers for measurement microphones, the new MV 240 is a 1/2" preamp that combines a high-impedance transducer with an analog-to-digital 24-bit converter. The output signal of the measurement microphone capsule is optimally adjusted to the dynamic range of the analog-to-digital converter by an impedance converter and a pre-amplifier with a very low noise level and THD.
An integrated processor combines the two different level ranges, from the capsule and converter to the one-channel 32-bit output signal. The pre-amplifier converts sound pressure levels from 7 dB to 160 dB, with a frequency range up to 80 kHz and generates internally a switchable 200V polarization voltage for the microphone capsule (this can be switched off when using electret measurement microphone capsules). The pre-amplifier supports 48 kHz, 96 kHz and 192 kHz sampling frequencies.
The MV 240 is powered by a USB interface, connected via a lockable LEMO connector and a special LEMO to USB adapter cable. No special hardware driver is needed with Windows, MacOS and Linux systems. A range of adapters allows to use the MV 240 with different 1", 1/4", and 1/2" measurement microphone capsules.