DOI: 10.25675/10217/233924
title: Dataset associated with "Design and Testing of a Low-Cost Sensor and Sampling Platform for Indoor Air Quality"

description: These data were collected during a study in which nine prototypes of a low-cost sensor and sampling platform---which was called the "Home Health Box" and was designed to measure concentrations of CO2, CO, NO2, O3, PM2.5, and PM10 in indoor air---were collocated with reference (i.e., research- and regulatory-grade) CO2, CO, NO2, O3, and PM2.5 monitors in the kitchen of a home in Fort Collins, Colorado, USA for one week in October 2020. The files associated with this dataset include: (1) raw CO2 concentrations measured using a LI-COR Biosciences LI-820 CO2 Gas Analyzer (the reference CO2 monitor); (2) raw CO concentrations logged by two TSI Incorporated QTrak 7575-X Indoor Air Quality Monitors with model 982 probes (the reference CO monitors); (3) raw PM2.5 concentrations logged by a ThermoFisher Scientific 1405 Tapered Element Oscillating Microbalance (the reference PM2.5 monitor); (4) the pre- and post- sampling masses of 37-mm diameter polytetrafluoroethylene filters used to sample PM2.5 and PM10 with the nine Home Health Boxes and one Access Sensor Technologies ASPEN box; (5) a log of activities that took place inside the home during the experiment; (6) calibration coefficients provided by the manufacturer (Alphasense) of the low-cost electrochemical CO, NO2, and O3 sensors used in the Home Health Boxes; (7) coefficients of linear mixed calibration models fit to relate CO2 concentrations reported by the low-cost nondispersive infrared (NDIR) sensors used in the Home Health Boxes to reference CO2 concentrations; (8) coefficients of linear mixed calibration models fit to relate data recorded by the low-cost electrochemical CO, NO2, and O3 sensors used in the Home Health Boxes to reference CO, NO2, and O3 concentrations; (9) processed time-series CO2, CO, NO2, O3, and PM2.5 concentration data obtained from the Home Health Boxes as well as the reference monitors; (10) raw NO and NOx concentrations measured using a Thermo Environmental Instruments Model 42C Trace Level Chemiluminescence NO-NO2-NOx Analyzer (the reference NO2 monitor); (11) raw O3 concentrations measured using a Thermo Environmental Instruments Model 49C UV Photometric O3 Analyzer (the reference O3 monitor); (12) all raw data logged by the nine Home Health Boxes; (13) raw data logged by a Access Sensor Technologies ASPEN box installed outside the home.
description: Americans spend most of their time indoors at home, but comprehensive characterization of in-home air pollution is limited by the cost and size of reference-quality monitors. We assembled small "Home Health Boxes" (HHBs) to measure indoor PM2.5, PM10, CO2, CO, NO2, and O3 concentrations using filter samplers and low-cost sensors. Nine HHBs were collocated with reference monitors in the kitchen of an occupied home in Fort Collins, Colorado, USA for 168 h while wildfire smoke impacted local air quality. When HHB data were interpreted using gas sensor manufacturers' calibrations, HHBs and reference monitors (a) categorized the level of each gaseous pollutant similarly (as either low, elevated, or high relative to air quality standards) and (b) both indicated that gas cooking burners were the dominant source of CO and NO2 pollution; however, HHB and reference O3 data were not correlated. When HHB gas sensor data were interpreted using linear mixed calibration models derived via collocation with reference monitors, root-mean-square error decreased for CO2 (from 408 to 58 ppm), CO (645 to 572 ppb), NO2 (22 to 14 ppb), and O3 (21 to 7 ppb); additionally, correlation between HHB and reference O3 data improved (Pearson's r increased from 0.02 to 0.75). Mean 168-h PM2.5 and PM10 concentrations derived from nine filter samples were 19.4 micrograms per cubic meter (6.1% relative standard deviation [RSD]) and 40.1 micrograms per cubic meter (7.6% RSD). The 168-h PM2.5 concentration was overestimated by PMS5003 sensors (median sensor/filter ratio = 1.7) and underestimated slightly by SPS30 sensors (median sensor/filter ratio = 0.91).