The use of cloth face coverings and face masks has become widespread in light of the COVID-19 pandemic. This paper presents a method of using low cost wirelessly connected carbon dioxide (CO₂) sensors to measure the effects of properly and improperly worn face masks on the concentration distribution of exhaled breath around the face. Four types of face masks are used in two indoor environment scenarios. CO₂ as a proxy for exhaled breath is being measured with the Sensirion SCD30 CO₂ sensor, and data are being transferred wirelessly to a base station. The exhaled CO₂ is measured in four directions at various distances from the head of the subject, and interpolated to create spatial heat maps of CO₂ concentration. Statistical analysis using the Friedman’s analysis of variance (ANOVA) test is carried out to determine the validity of the null hypotheses (i.e., distribution of the CO₂ is same) between different experiment conditions. Results suggest CO₂ concentrations vary little with the type of mask used; however, improper use of the face mask results in statistically different CO₂ spatial distribution of concentration. The use of low cost sensors with a visual interpolation tool could provide an effective method of demonstrating the importance of proper mask wearing to the public.

中文翻译：

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一套多个低成本二氧化碳传感器，用于测量具有面罩类型和佩戴行为的呼出气分布

鉴于 COVID-19 大流行，布面罩和口罩的使用已变得普遍。本文提出了一种使用低成本无线连接的二氧化碳 (CO ₂ ) 传感器来测量正确和不正确佩戴口罩对面部周围呼出气浓度分布的影响的方法。四种类型的口罩用于两种室内环境场景。CO ₂作为用于呼出气体的代理是与所述的sCD30 Sensirion公司测量CO ₂传感器，并且数据被无线地传输到基站。呼出的 CO ₂在距受试者头部不同距离的四个方向上进行测量，并进行插值以创建 CO _{2 的}空间热图专注。使用弗里德曼方差分析（ANOVA）检验进行统计分析以确定不同实验条件之间的零假设（即，CO _{2 的}分布相同）的有效性。结果表明 CO ₂浓度随所用面罩类型的不同而变化不大；然而，不正确使用面罩会导致 CO ₂浓度空间分布在统计上有所不同。使用带有视觉插值工具的低成本传感器可以提供一种有效的方法，向公众展示正确佩戴口罩的重要性。