G.R.A.S. 40PL CCP Free-field Array Microphone, High Pressure

Freq range: 50 to 20 kHz
Dyn range: 32 dB(A) to 150 dB
Sensitivity: 10 mV/Pa

Typical applications and use

  • Multi-channel measurements
  • Sound-field analyses
  • Sound-power measurements
  • Concurrent spatial and transient measurements


Array microphones are designed to be mounted on large or small arrays. Such systems are typically used for measuring and locating noise sources, and here the phase match is important to get good accuracy in the measurements. An important characteristic of array microphones are precisely that the microphones are phase-matched.

40PL has a dynamic range from 32dBA to 150dB peak, the upper limit is the peak value before visible clipping

40PL has an integrated CCP preamplifier and is delivered with a built-in TEDS chip which enables it to be programmed as a complete unit. The G.R.A.S. 40PL requires a constant current power supply, e.g. the G.R.A.S. 12AL CCP Supply, or any other CCP compatible power supply.

Close manufacturing tolerances together with the advantages of the TEDS chip provide the G.R.A.S. 40PL with a high degree of interchangeability; a major advantage when used in multiples forming arrays and matrices.

The low cost of the G.R.A.S. 40PL is a key consideration when setting up measurements requiring a multiplicity of concurrent transient and spatial data.

Calibrating the G.R.A.S. 40PL with a G.R.A.S. pistonphone (G.R.A.S. 42AP is recommended) is as straightforward as calibrating any other G.R.A.S. 1/4-inch microphone.

All G.R.A.S. microphones are individually checked and calibrated before leaving the factory. An individual calibration chart is supplied with each microphone.

Frequency range (±1 dB) Hz 50 to 5 k
Frequency range (±2 dB) Hz 5 k to 20 k
Frequency range (±3 dB) Hz 10 to 50
Dynamic range lower limit (microphone thermal noise) dB(A) < 32
Dynamic range upper limit dB 142
Set sensitivity @ 250 Hz (±3 dB) mV/Pa 10
Power supply (Constant Current Power) mA 2 to 20
Power consumption mA 2 to 20
Microphone venting Front
Output impedance Ω < 50
Temperature range, operation °C / °F -10 to 50 / -50 to 122
Temperature range, storage °C / °F -40 to 85 / -40 to 185
Influence of axial vibration @1 m/s² dB re 20 µPa 50
TEDS UTID (IEEE 1451.4) 27 v. 1.0
Connector type SMB
CE/RoHS compliant/WEEE registered Yes / Yes / Yes
Weight g / oz 5.5 / 0.2

Phase Match


50Hz  - 100Hz


100Hz  - 3kHz


3kHz  - 5kHz


5kHz  - 10kHz


 Frequency response

Typical frequency response

----  Pressure response

___  Free-field response

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


Optional items

G.R.A.S. AA0027

3 m SMB - BNC Cable

G.R.A.S. 12AL

1-Channel CCP Power Module with A-weighting filter

G.R.A.S. PR0002

Array Module

G.R.A.S. AM0364

Windscreens (set of 6)

G.R.A.S. RA0092

Rain-protection cap

G.R.A.S. 42AA


G.R.A.S. 42AB

Sound Calibrator, Class 1

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