With an increase in understanding of how carbon dioxide (CO2) levels affect indoor air quality (IAQ), there is a growing need for reputable and capable forms of indoor CO2 measurement. Several different forms of CO2 sensors have successfully been presented to date, such as non-dispersive infrared (NDIR), photoacoustic, electroacoustic, and electrochemical sensors; however, few of these are suitable for precision tasks while remaining low-cost and low-power. In recent years, there has been a progressive increase in understanding of the use of small-scale resonant gas sensors, creating a low-cost, low-power, alternative to these previously mentioned technologies. Such sensors utilize small-scale resonators, functionalized to have a chemical affinity for select gas analytes. This attraction induces a change in the resonant frequency of the device, which indicates the presence of the analyte.This work presents research on a resonant mass CO2 sensor, functionalized with a blend of (poly)ethylenimine (PEI) and (poly)ethylene oxide (PEO). For relevance in IAQ monitoring and building applications, a variety of testing scenarios are required. Among these, a comprehensive understanding of how temperature and humidity affect sensor behavior is non-negotiable as modern building heating, ventilation, and air conditioning (HVAC) systems are capable of managing a vast array of environmental conditions. Thus, the resonant mass sensors presented herein were exposed to an array of temperatures and relative humidity conditions that simulate a building environment.

Exploring the Influence of Temperature and Humidity on a Resonant Mass Co2 Sensor for Buildings

Paper Proceedings: https://asmedigitalcollection.asme.org/IDETC-CIE/IDETC-CIE2021/volume/85369

ASME 2021 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC/CIE2021)

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.