Measurement Microphone Preamplifier MV 240 digital

Please note that this package includes the USB Pre-amp without capsule

The 1/2“ measurement microphone pre-amplifier type MV 240 digital combines a high-impedance transducer with an analog-to-digital 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. One channel of a 24 bit analog-to-digital converter converts the lower level range of the capsule signal and the other channel the upper level range. A following processor combines these two level ranges to the one-channel 32 bit output signal, that represents calibrated sound pressure levels. The MV 240 digital converts sound pressure levels from 7 dB to 160 dB – more than the complete dynamic range of a typical 1/2“ measurement microphone capsule. The pre-amplifier supports the sample frequencies 48 kHz, 96 kHz and 192 kHz. Measurements up to 80 kHz are possible with 1/4“ measurement microphone capsules.

For the use of the MV 240 digital no special hardware driver is necessary because it is detected automatically by the operating system and can be used with Windows, MacOS and Linux. The MV 240 digital is powered by the USB interface and generates internally 200 V polarisation voltage for the measurement microphone capsule that can be switched off when using electret measurement microphone capsules. The pre-amplifier is connected to the USB interface via a lockable LEMO® connector and a special LEMO® to USB adapter cable. Two integrated generators can be used to check the 32 bit processing of the following signal chain and to detect the reference value for a sound pressure of 1 Pascal.

The MV240 has the following unique features:

• integrated DC/DC converter for 200V polarisation voltage (can be switched off)
  
• Full dynamic in ONE measurmeent range
  
• stable LEMO connector (LEMO ->USB cable is included)
• calibration data is stored inside the microphone
  
• low self noise  7dB(A) with repect to 50mV=94dB. Mesured with replacement capsule.
  

Technical specification:

• ADC    Sigma-Delta-ADC, 24 Bit, 192 kHz
• 2 level ranges (an internal DSP computes one high dynamic measurement range)
  
• Output signal    USB, 1 channel, 32 Bit
• calibrated sound pressure values
• Power supply    5 V (±5%)
• Current consumption    500 mA (at Ui = 10 Vrms)
• Frequency range    1 Hz to 80 kHz
• Inherent noise    A-weighted    7 dB
• Max. SPL        160 dB
• Maximum input        10 Vrms
• Input impedance    20 GOhm; 0.2 pF
• Sample rate    192 kHz
• Polarization voltage    200 V
• Remote control        polarisation voltage on / off
• Connection to        USB 2.0 / USB 3.0
• Plug    4-pin LEMO® EGG.1B.304.CLL
• Capsule thread    11.7 mm 60 UNS
• Diameter    12.7 mm / 21 mm
• Length    184 mm
• Weight    115 g