GRAS 40PM EQset ${ }^{\text {TM }}$ Miniature Production Line Microphone

1. EQset ${ }^{\text {TM }}$

EQset is a technology that eliminates unnecessary production line stoppages for calibration, ensuring consistent and valid data. This significantly reduces the likelihood of false failures or passes. Calibration is only required to verify functionality and validate the entire measurement chain, as the EQset microphone effectively equalizes the signal before it reaches the analyzer.

1.1 No need for TEDS

EQset guarantees a flat response curve and uniform sensitivity for each microphone. The consistency among microphones allows for data traceability without the need to track individual microphone placement. Consequently, there is no requirement to identify specific microphones and apply corrections based on their individual sensitivities and response curves.

2. 40PM

The 40PM microphones with EQset are engineered for production line environments. They are designed to be cost-effective, user-friendly, error-resistant, and environmentally stable. The tolerance for individual microphone sensitivities is less than $\pm 0.2 \mathrm{~dB}$, and the frequency response variation is less than $\pm 0.5 \mathrm{~dB}$ up to 10 kHz. As the 40PM is dimensionally identical to traditional production line microphones, it can be easily integrated into existing setups.

3. Setup and use with APx517B analyzer

Setting up and measuring with 40PM microphones is straightforward:

1. Place the microphone at the test station as required by the measurement standards.
2. Connect the cable to the microphone.
3. Set the sensitivity in the APx500 software:
   • Navigate to the Signal Path Setup panel > Input Configuration > Input 1 tab.
   • Set the Measure control to 'Acoustic'.
   • Set the Sensitivity to $25.00 \mathrm{mV} / \mathrm{Pa}$ for the channel used with the microphone (e.g., Channel 1).

A textual description of the Signal Path Setup panel shows Input Configuration with options for Input 1 and Input 2. Under Input 1, 'Measure' is set to 'Acoustic', and 'Sensitivity' for Channel 1 is set to '25.00 mV/Pa'.

A textual description of the APx Set Acoustic Output Level dialog shows options to 'Regulate' by 'RMS Level' to a 'Target Value' of '+80.000 dBSPL'. It allows selection for 'On:' channel with highest value, lowest value, or a specific channel (Ch1). 'Adjust' can be set to 'Gen Level', with 'Start Value' of '1.000 mVrms', 'Stop Value' of '200.0 mVrms', 'Initial Steps' of '2', and 'Frequency' of '1.00000 kHz'. Buttons for 'Start', 'Close', and 'Help' are present.

4. Set the Acoustic Output Level of the power amplifier:

   NOTE: Ensure the microphone is connected and set up as per Step 3 before adjusting the acoustic output level.

   • Check the 'Acoustic' checkbox in the Signal Path Setup panel > Output Configuration.
   • Click the 'Acoustic Output Level' button to open the 'Set Acoustic Output Level' dialog. Refer to the APx500 documentation for details on regulating the generator level for acoustic measurements.
5. Perform measurements according to your standard procedures.

4. Key specifications

*Typical environmental conditions on a production line include temperature variations between 13 and $35^{\circ} \mathrm{C}$ (55 to $95^{\circ} \mathrm{F}$), static pressure variations between 983 and 1043 hPa, and non-condensing humidity.