The EX378B02 is an INDUSTRY EXCLUSIVE prepolarized condenser microphone system. It is Hazardous Areas & Explosive Atmospheres compliant and can safely be employed in gaseous hazardous environments where standard microphones may cause a spark and fire. The EX378B02 is equipped with a Free-field microphone cartridge and complies with Intrinsic Safety Protection Levels for all above ground applications globally, and complies with below ground Very High (Ma) Mine Safety protection levels for all mining locations outside of North America.

This design utilizes PCB’s most popular microphone cartridge, an IEC 61094-4 working class compliant ½” Free-field prepolarized microphone, model 377B02. We place this 0V microphone into a spark resistant package that complies with ATEX, IECEx, EN (International), and ETL (Domestic) North American standards, resulting in the world’s first test and measurement grade condenser microphone and preamplifier combination designed for hazardous areas.


  • ATEX, IECEx, and ETL c/us approvals
  • I M1 Ex ia I T4 -40°C = Tamb = 80°C
  • Class 1, Division 1, Groups A, B, C,
    and D
  • Class 1, Zone 0, AEx ia/Ex ia IIC T4 Ga
  • Prepolarized (0V) design
  • 15.5 dBA to 137 dB capability
  • High sensitivity, 50 mV/Pa
  • Uses cost effective coaxial cables
  • A2LA, ILAC accredited
  • CE MARKED, RoHS Compliance


  • Leak detection
  • Mine safety
  • Gas tank testing
  • Environmental noise monitoring
  • Measurements in potentially
    hazardous areas


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Model NumberEX378B02
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Price:$1,950.00 USD
Nominal Microphone Diameter1/2"
Frequency Response Characteristic (at 0° incidence)Free-Field
Sensitivity (±1.5dB)-26 dB re 1 V/Pa
Sensitivity50 mV/Pa
Frequency Range (±2dB)3.75 to 20000 Hz
Frequency Range (±1dB)7 to 10000 Hz
Lower Limiting Frequency1.0 to 3.0 Hz
Inherent Noise15.5 dB(A) re 20 µPa
Dynamic Range (3% Distortion Limit)137 dB re 20 µPa
Temperature Range (Operating)
-40 to +176 °F
-40 to +80 °C
Temperature Coefficient of Sensitivity (+14 to +158°F (-10 to +70°C))
0.005 dB/°F
0.009 dB/°C
Static Pressure Coefficient-0.013 dB/kPa
Humidity Coefficient of Sensitivity (0 to 100%, non-condensing)±0.001 dB/%RH
Influence of Axial Vibration (0.1g (1 m/s²))63 dB re 20 µPa
Polarization Voltage0 V
Excitation Voltage20 to 30 VDC
Constant Current Excitation2 to 20 mA
Output Bias Voltage10 to 14 VDC
Maximum Output Voltage±7 Vpk
Output Impedance<50 Ohm
Housing MaterialStainless Alloy
Electrical ConnectorBNC Jack
Mounting Thread (Grid)0.5 - 60 UNS
Size - Diameter (with grid)
0.52 in
13.2 mm
Size - Diameter (without grid)
0.50 in
12.7 mm
Size - Height (with grid)
4.02 in
102.1 mm
Size - Height (without grid)
3.99 in
101.2 mm
1.87 oz
53 gm