Laboratory Performance Evaluation of a Low-Cost Electrochemical Formaldehyde Sensor

Abstract

Formaldehyde is a known human carcinogen and an important indoor and outdoor air pollutant. However, current strategies for formaldehyde measurement, such as chromatographic and optical techniques, are expensive and labor intensive. Low-cost gas sensors have been emerging to provide effective measurement of air pollutants. In this study, we evaluated eight low-cost electrochemical formaldehyde sensors (SFA30, Sensirion®, Staefa, Switzerland) in the laboratory with a broadband cavity-enhanced absorption spectroscopy as the reference instrument. As a group, the sensors exhibited good linearity of response (R2 > 0.95), low limit of detection (11.3 ± 2.07 ppb), good accuracy (3.96 ± 0.33 ppb and 6.2 ± 0.3% N), acceptable repeatability (3.46% averaged coefficient of variation), reasonably fast response (131–439 s) and moderate inter-sensor variability (0.551 intraclass correlation coefficient) over the formaldehyde concentration range of 0–76 ppb. We also systematically investigated the effects of temperature and relative humidity on sensor response, and the results showed that formaldehyde concentration was the most important contributor to sensor response, followed by temperature, and relative humidity. The results suggest the feasibility of using this low-cost electrochemical sensor to measure formaldehyde concentrations at relevant concentration ranges in indoor and outdoor environments.

Multi-Sensor Device for Traceable Monitoring of Indoor Environmental Quality

“…An electrochemical sensor was installed in the PROMET&O multi-sensor to measure this parameter. This typology of the sensor can have high selectivity and accuracy [39]. However, crafting sensors capable of accurately measuring formaldehyde levels at low concentrations has proven to be complex.…”

“…There is potential for the development of more advanced models to assess sensor performance in ambient conditions. It is worth noting that specific accuracy criteria for low-cost formaldehyde sensors have yet to be established [39].…”

Fluorinated TiO2 Hollow Spheres for Detecting Formaldehyde under UV Irradiation

“…However, electrochemical gas sensors still suffer from high cross-sensitivity issues. The commercial electrochemical formaldehyde sensor SFA30 (Sensirion) with low detection limits (20 ppb) is also sensitive to CO, NO, and NO 2 gases and has been reported by Pei et al [19]. In addition, compared with optical sensors and electrochemical sensors, semiconductor gas sensors are the most widely used gas sensors because of their advantages of high sensitivity, low cost, easy large-scale preparation, easy operation, and small size.…”

Effect of Three-Dimensional-Printed Thermoplastics Used in Sensor Housings on Common Atmospheric Trace Gasses

“…Additionally, low-cost sensors have enabled the creation of large sensor networks that augment established government monitoring sites and increase the spatial distribution of measurements [ 5 , 6 , 7 , 8 ]. Simultaneously, 3D printing, particularly fused deposition modeling (FDM) using thermoplastic filaments, has emerged as an economical means to craft customized structural supports and sensor housings for air quality research applications [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ].…”