Product Overview
The G.R.A.S. Microphone Type 40DP is a ⅛-inch pressure microphone designed for high-frequency and high-level sound measurements. Its small size minimizes diffraction and reflection effects, making it suitable for precise sound field measurements.

Specifications

• Sensitivity: 1 mV/Pa at 250 Hz
• Frequency Response: 10 Hz to 30 kHz (±1.0 dB), 6.5 Hz to 140 kHz (±2.0 dB)
• Polarization Voltage: 200 V
• Dynamic Range: Upper limit at 174 dB re. 20 µPa (3% distortion), Lower limit at 40 dBA re. 20 µPa (thermal noise)
• Resonant Frequency: 160 kHz (90° phase shift)
• Dimensions: Length 6.7 mm, Diameter 3.5 mm (with protection grid)
• Weight: 1.5 g
• Temperature Range: -40 °C to +150 °C

Applications

• Sound-pressure measurements
• High-frequency measurements
• Very high-level pressure measurements
• Impulse-noise measurements

Compatibility and Construction
The microphone requires an adapter (RA0063 or RA0082) for mounting onto ¼-inch preamplifiers. It is compatible with G.R.A.S. preamplifiers Types 26AA, 26AB, 26AC, and 26AL. Constructed from non-corrosive stainless materials, it is durable in harsh environments.

Warranty and Calibration
All G.R.A.S. microphones come with a 5-year warranty and are individually calibrated before dispatch.