GRAS Sound & Vibration’s new measurement microphones

These two new miniature microphones are designed for final tests in the production line of audio devices. Both microphones are part of the GRAS microphone family equipped with the GRAS EQset technology, launched in January 2023. This revolutionary technology uses a built-in Digital Signal Processing (DSP) module to flatten the frequency response of the microphone and adjust its gain. This way, all microphones of the same type that use GRAS EQset are virtually the same as each other. From the user’s perspective, both GRAS 40PM and 40PM-1 microphones still provide an analog output so it can be used to replace traditional production line microphones.

On top of that, production line microphones with GRAS EQset technology provide high environmental stability, consistent sensitivity and frequency response across their entire frequency range right out of the box. All these will help the users of these microphones simplify their test setup, reduce downtime, simplify calibration procedures, and reduce test results uncertainty. All these new revolutionary features of these new microphones have been added without sacrificing the cost-effectiveness of the microphone. Overall, a perfect solution to increase efficiency and save valuable resources.

Measurement microphones for the production line need to be cost-efficient. This is usually translated into a microphone that will have large tolerances in its frequency response and sensitivity. This means that there could be significant variations from one microphone to another of the same type. EQset technology solves this issue, by providing a sensitivity tolerance of ±0.2 dB and frequency response tolerance of ±0.5 dB for 40PM-1. In contrast, traditional production line microphones can have sensitivity tolerances of ±3dB and frequency response tolerances up to ±2/3dB. The cost-effective components typically used with traditional production line microphones will also affect the microphone’s environmental stability. This means that the frequency response and sensitivity of the microphone can vary over time with changing environmental conditions (temperature, humidity and/or static pressure), or that the microphone can behave differently if used in places with different environmental conditions (e.g. two production lines placed in different places of the world).

The GRAS EQset microphones have a new cartridge design and electronics, that increases the environmental stability of the microphone to a category previously unthinkable on production-line microphones. The exceptional environmental stability of GRAS 40PM and 40PM-1 EQset microphones means that under typical production line environmental conditions the sensitivity of the microphone will not vary more than ±0.3 dB for 40PM and ±0.2 for 40PM-1.

Find out more: https://www.grasacoustics.com/products/eqset-production-line-microphones/product/854-gras40pm-eqset