Product Overview
The G.R.A.S. ½-inch Wide-frequency, Pressure Microphone Type 40AG is a precision reference microphone designed for laboratory use, including applications in couplers, ear simulators, enclosures, and at boundaries. It is an externally polarized pressure microphone known for its large dynamic range and extended frequency response.

Specifications

• Frequency Response: 3.15 Hz - 20 kHz (± 2.0 dB), 5 Hz - 12.5 kHz (± 1.0 dB)
• Nominal Sensitivity: 12.5 mV/Pa
• Polarization Voltage: 200 V
• Dynamic Range: Upper limit at 160 dB re. 20 µPa with 3% distortion
• Microphone Thermal Noise: 20 dBA re. 20 µPa
• Capacitance: 20 pF
• Temperature Range: -40 °C to +150 °C
• Dimensions: Length with protection grid: 12.5 mm, Diameter: 13.2 mm
• Weight: 7 g
• Temperature Coefficient: -0.002 dB/°C
• Static-pressure Coefficient: -0.008 dB/kPa
• Humidity Range: 0 - 100% (non-condensing)
• Influence of Humidity: < 0.1 dB (0 - 100% RH)
• Influence of Axial Vibration: 66 dB re. 20 µPa
• Venting: Rear vented
• IEC 1094-4 Type Designation: WS2P

Applications
Typical applications include precision sound pressure measurements, very high frequency measurements, laboratory reference measurements, and use in couplers and ear simulators.

Compliance and Durability
All G.R.A.S. microphones comply with IEC 1094 standards for measurement microphones and are made from non-corrosive, stainless materials to withstand rough handling and corrosive environments. Each microphone is guaranteed for 5 years and comes with an individual calibration chart.

Additional Information
G.R.A.S. offers compatible preamplifiers for use with the Type 40AG, and the microphone's mounting thread is compatible with other similar preamplifiers. The document includes figures illustrating the typical frequency response and free-field corrections for various angles of incidence.