Testing with Class 1 Sound Calibrator

This article demonstrates the accuracy of the PCBA-DBM-r3 by testing it with a sound level calibrator.
The calibrator produces 94 dB SPL test tones at 1 kHz, 500 Hz, 250 Hz, and 125 Hz to test the module’s measurement and weighting accuracy at different frequencies.
The acoustic calibrator used (AWA6223+ multi-frequency calibrator) is IEC 60942:2017 Class 1 compliant and dynamically compensates for environmental factors like temperature, humidity and atmospheric pressure for accurate calibration tone generation.

💡 TIP
This article on Frequency Weightings by NTI Audio lists “frequency vs weights” used for A-, C-, and Z-weighting in accordance with the IEC 61672:2014 standard.

Test Setup

For testing, the PCBA-DBM-r3 sound level meter module is attached to the AWA6223+ acoustic calibrator using an adapter and sealing gasket. The readings produced by the PCBA-DBM-r3 are read and displayed on demo hardware with a display. The test setup is shown in the picture below.

The touch GUI has buttons to select frequency weights for easy testing.

A-Weighting Mode

Similarly, readings for C-weighting and Z-weighting were also recorded and are listed below.

C-Weighting Mode

Z-Weighting Mode