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Ultrasonic Microphone USB - Industrial Grade

The 1/4” microphone cartridge MK 301 E is designed for ultrasound measurements up to 100 kHz in research and development and also for industrial use. Some applications include audiology, the measurement of building acoustics and noise levels.

The microphone cartridge has a fixed layer of backelectret to supply the polarization voltage.

It is designed and very carefully constructed to ensure excellent long-time stability of the electroacoustical parameters. 

All essential components including the diaphragm are made of nickel and the diaphragm is bonded by a special galvanic process. 

The rear electrode is insulated from the cartridge housing by a quartz glass plate. The diaphragm is protected against mechanical damage by a protection grid. 

The equalization of the static air pressure between the inside and outside of the cartridge is by means of a capillary tube rear-vented into the preamplifier.

The cartridge uses the international standard thread 60 UNS which ensures compatibility with a wide range of calibration equipment and measurement devices available from many manufactures.

The measuring microphone cartridge MK 301 is designed for sound level meters of IEC Type 1 according to IEC 6

Ultrasonic Microphone USB


  • Class 1 WS3F acc. IEC 61094-4
  • Frequency range 5 Hz to 80 kHz
  • Free Field
  • Sound pressure level up to 168 dB
  • 35dBA to 168dB
  • Pre-polarized 

Ultrasonic noise of a mini PC with relatively high noise level of 54 dB at 44 000 Hz


Measuring chain was calibrated with CA111 sound level meter calibrator before measurement

Frequency response up to 80 kHz – sampling frequency = 192 kHz

Ultrasound Microphone 5 Hz to 100 kHz
MK 301 E
WS3F – IEC 61094-4
Frequency Range
5 Hz … 100 kHz (± 2 dB)
Responce Type
pressure transducer
Electrode Forming Voltage
0 V
Sensitivity (dB re 20 μPa)
3.5 mV/Pa (± 3 dB)
Capacitance at 1 kHz
4.5 pF
Max. SPL for THD
≤ 3 % at 1 kHz
168 dB peak
Intrinsinc Noise Level
36 dB (A)
Operating Temperature Range
-20 °C ~ +100 °C
Operating Humidity Range
25 % ~ 90 %(RH)
Storage Humidity Range
25 % ~ 90 %(RH)
Outer Dimensions
with protection grid
Ф 7 mm x 9.7 mm
± 0,02 mm
2 gram
USB Microphone
Signal Amplitude ref. 50mV @ 1kHz
Frequency Response
Frequency Sampling 192 kHz
1Hz~20Hz, Error <3.0dB
20Hz~20kHz, Error<0.3dB
20kHz~80kHz, Error<3.0dB
Electrical signal
noise background
Ch.1 (<13dBA, <26dBZ)
Ch.2 (<50dBA, <63dBZ)
THD Input 1kHz, 50mV, A weighting
Overload Indicator
1kHz (THD<3%)
Ch.1 (>101.9dB)
Ch.2 (>140dB)
Amplitude accuracy
Input 31.6mV, 1kHz, 90.0dB
Error <0.2dB
1/2″ Outer diameter
of protector cover
Ф 20 × 165 mm
φ 13.2mm
<96 g (cable not included)
Operating Temperature
-20°C ~ + 60°C
25 %~ 90 %(RH)
Atmospheric Pressure
65 kPa~108 kPa
Connector Type
Microphone Thread
11.7 mm-60 UNS