GRAS 40PH CCP Free-field Array Microphone

Typical applications and use

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

Design

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.

40PH has a wide useful frequency range reaching up to 20 kHz and a large dynamic range topping at around 135 dB,  the peak value before visible clipping.

It 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 GRAS 40PH requires a constant current power supply, e.g. the GRAS 12AL CCP Supply, or any other CCP compatible power supply.

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

The low cost of the 40PH is a key consideration when setting up measurements requiring a multiplicity of concurrent transient and spatial data.

Calibrating the 40PH with a GRAS pistonphone, e.g. GRAS 42AA, is as straight forward as calibrating any other GRAS 1/4-inch microphone.

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