Renesas Unwraps MCU-Based Sensor Module for Smart Air Quality Monitoring

Renesas has released the RRH6200, an air quality monitoring module that uses a broad range of sensors and embedded processing to detect harmful particulates, total volatile organic compounds (VOCs), and other determinants of air quality in homes, schools, and public buildings.

RRH62000 air quality sensor module. 

Following the COVID-19 pandemic, the public is increasingly concerned with maintaining high air quality in enclosed spaces. Air pollutants can impact respiratory health, and pollutants such as dust, paint fumes, smoke from cooking, pollen, and particulates from HVAC filters can be six to ten times more concentrated in indoor spaces. 

With a compact footprint of only 46.6 mm x 34.8 mm x 12 mm, the RRH620000 packs a payload of sensors to detect particulate matter and other harmful pollutants and estimate key environmental parameters such as CO2, temperature, and humidity. The RRH620000 also provides real-time environmental information to help engineers and building operators meet and maintain air quality standards within indoor and enclosed spaces.   

How the RRH62000 Works

The RRH62000 module (datasheet linked) integrates multiple sensors that can measure particulate matter (PM), total volatile organic compounds (TVOC), indoor air quality index (IAQ), carbon dioxide (eCO2), temperature (T), and relative humidity (RH).

RRH62000 functional block diagram

The sensor draws in air using an integrated high-speed fan where optical (laser) circuits excite and detect airborne particulates. Onboard gas (ZMOD4410) and humidity (HS4003) sensors measure and provide TVOC, eCO2, temperature, and humidity data. 

The onboard sensors can detect particles as small as 0.3 µm, segregating them into three mass concentration bins for particles up to 10 µm. TVOCs can be detected down to 160 parts per billion (ppb), and the IAQ index is measured under German Federal Environmental Agency standards. Sensor data is relayed to the onboard MCU for processing and can then be communicated to the system host processor via I2C and UART interfaces.

Beyond Environmental Data

The RRH62000 provides more than just environmental data. Onboard output correction algorithms correlate data between sensors to improve their individual accuracy and help identify detectable contaminants. The MCU also handles on-module control and arithmetic functions to deliver actionable information to the host processor, freeing up its limited capacities.

Correlating elevated CO2 from room occupancy to TVOC

While the RRH62000 cannot measure CO2 levels directly, Renesas has developed a proprietary algorithm that correlates elevated CO2 levels associated with room occupancy with measured TVOC levels. The effective measurement range for eCO2 is 400 ppm up to 5,000 ppm.