G.R.A.S. 67AD ø400 mm CCP Ground Array Microphone Kit

Freq range: 3.15 Hz to 10 kHz
Dyn range: 18 dB(A) to 138 dB
Sensitivity: 50 mV/Pa

Typical applications and use

  • Ground array measurements
  • General noise measurements
  • Ideal for the aerospace industry

Design

The microphone set is designed to sit asymmetrically in the mounting to attain a more uniform frequency response for measurements.

The microphone is a IEC 61094 prepolarized pressure microphone with a dynamic range from 22 dB to 146 dB and a frequency range from 3.15 Hz to 20 kHz. Its height of only 8 mm (to the diaphragm) is the ideal match for the design of the 67AD. The built-in preamplifier is a low noise constant current power (CCP) type, with a built-in TEDS circuit for automatic transducer identification.

Frequency range (±1 dB) Hz 12.5 to 7 k
Frequency range (±2 dB) Hz 3.15 to 10 k
Dynamic range lower limit (microphone thermal noise) dB(A) 18
Dynamic range upper limit dB 138
Set sensitivity @ 250 Hz (±2 dB) mV/Pa 50
Polarization voltage V 0
Power supply (Constant Current Power) mA 2 to 10
Microphone venting Rear
Output impedance Ω <50
Temperature range, operation °C / °F -30 to 70 / -22 to 158
Temperature range, storage °C / °F -40 to 85 / -40 to 185
Static pressure coefficient @250 Hz dB/kPa -0.008
Humidity range non condensing % RH 1 to 100
Humidity coefficient @250 Hz dB/% RH < 0.1
Influence of axial vibration @1 m/s² dB re 20 µPa 66
TEDS UTID (IEEE 1451.4) 27 v. 1.0
Connector type Microdot 10/32
CE/RoHS compliant/WEEE registered Yes/Yes/Yes
G.R.A.S. Sound & Vibration reserves the right to change specifications and accessories without notice.

Included items

G.R.A.S. 47AX-S1 1/2'' CCP Flush-mounted Microphone Set
G.R.A.S. GR1425 Ground plate Ø400 mm
G.R.A.S. AM0375 Windscreen for 67AX
G.R.A.S. AA0069 3 m Microdot Angled - BNC cable

Optional accessories

G.R.A.S. 42AP Intelligent Pistonphone, Class 0
G.R.A.S. RA0216 Pistonphone field-verification adapter
G.R.A.S. RA0221 Pistonphone calibration adapter

G.R.A.S. Sound & Vibration reserves the right to change specifications and accessories without notice.