Airgreen is preparing the GN25 Series Noise Monitoring Module for launch. Developed for construction-site and environmental noise monitoring, the new module aligns its core measurement and evaluation workflow with GB 12523-2025, the updated Chinese standard for construction noise emissions.
From real-time sound levels to traceable noise events
The GN25 is designed as a compact measurement core for online noise terminals, data loggers, construction-site environmental monitoring systems and industrial control platforms. It synchronously measures A-, C- and Z-frequency-weighted sound levels, with real-time values refreshed approximately every 20 ms.
For construction-noise evaluation, the current OTA 88.1.1 firmware exposes complete 20-minute equivalent and maximum sound-level results. Measurement periods are aligned to 00-20, 20-40 and 40-60 minute segments, helping monitoring platforms maintain consistent time-based records.
Built for the new construction-noise workflow
- Synchronous A/C/Z measurement: compare conventional A-weighted results with low-frequency and unweighted sound-pressure characteristics.
- Day and night evaluation: supports automatic time-period recognition and status reporting for daytime and nighttime limits.
- Background-noise correction: supports 10- or 20-minute background measurement, result storage and correction control.
- Field calibration: supports pre-measurement calibration and post-measurement verification. The default calibration target is 94.0 dB, with a verification pass threshold of 0.5 dB.
- Alarm-triggered recording: configurable event recording from 0 to 600 seconds when an SD card is available, supporting later source identification and incident review.
- System diagnostics: reports measurement state, RTC faults, SD-card status and result-validity information.
Designed for straightforward system integration
The module uses RS485 / Modbus RTU communication and supports function codes 03/04 for reading and 06/10 for writing. The current firmware defines 40 registers from 00000 to 00039. Default communication is slave address 1, 9600 baud and 8N1, making the module suitable for PLCs, data acquisition equipment and host-computer software.
Airgreen will publish final ordering information, confirmed hardware specifications and release documentation after product validation is complete.