Chaparral Physics 64Vx2

Salient Features:

The Chaparral Physics Model 64Vx2 Infrasound Sensor is a compact, lightweight, and rugged broadband microphone engineered to detect ultra-low frequency atmospheric pressure waves (infrasound) across a wide spectral range. Often described as a microbarometer or ultra-low frequency microphone, the 64Vx2 is suitable for applications in volcanology, atmospheric research, explosive event detection, and environmental monitoring.

With a bandwidth of 0.03 Hz to 245 Hz, nominal sensitivity of 0.03 V/Pa, and a dynamic range of 118 dB, the Model 64Vx2 is optimized to detect both the smallest and most extreme signals in demanding field environments—from Arctic tundra to rainforest ecosystems.

Key Specifications:

• Frequency Response: Flat within ±3 dB from 0.03 Hz to 245 Hz

• Sensitivity: 0.03 V/Pa at 1 Hz; up to 720 Pa peak-to-peak full-scale input range

• Noise Floor: ~1.8 mPa RMS (0.1–200 Hz), 0.4 mPa RMS (0.5–2 Hz)

• Output: Differential; 22 V peak-to-peak maximum

• Power: <150 mW, 12 mA @ 12.6 V DC

• Size & Weight: 3.75” diameter, 3.1” height; 1.25 lbs (0.57 kg)

• Environmental Rating: IP-67 (sealed against moisture and dust)

• Operating Temperature: -40°C to +65°C

Despite its palm-sized profile, the sensor maintains the wide bandwidth, low seismic sensitivity, and environmental robustness expected from all Chaparral Physics instruments. Its integrated 3-port acoustic manifold and extremely low power draw (<150 mW) allow for streamlined deployments, including lightweight sensor arrays and portable kits.

Installation Tips

• Quick Field Deployment: Place the sensor with acoustic inlets facing downward on a level surface clear of debris. Covering it with a perforated plastic container can help reduce weather exposure while maintaining airflow.

• Wind Noise Reduction Arrays: Connect garden-hose-threaded tubing to the 3-port manifold for interfacing with wind noise reduction systems. This dramatically improves signal clarity in high-wind environments.

• Thermal Stability Matters: For permanent setups, house the sensor inside an insulated vault to maintain thermal equilibrium and protect from weather. Connect inlet ports to external arrays via tubing for optimal airflow isolation.

• Orientation & Shielding: Use a foam shield or stake the sensor when necessary to reduce mechanical noise or overturning risks. Avoid exposing the unit to rapid temperature shifts (>1°C/hour) for best low-frequency performance.

Manufacturer’s Documents

You can access the full product documentation here: