Efficacy of Paired Electrochemical Sensors for Measuring Ozone Concentrations.
Efficacy of Paired Electrochemical Sensors for Measuring Ozone Concentrations.
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成对电化学传感器测量臭氧浓度的功效。
DOI：
10.1080/15459624.2018.1540872
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发表时间：
2019
影响因子：
2
通讯作者：
Koehler,Kirsten
中科院分区：
文献类型：
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作者：
Zuidema,Christopher;Afshar-Mohajer,Nima;Tatum,Marcus;Thomas,Geb;Peters,Thomas;Koehler,Kirsten
典型的低成本臭氧 (O3) 电化学传感器对二氧化氮 (NO2) 也具有高度响应性。因此，单个传感器对 O3 的响应与对 NO2 的响应无法区分。最近，一种量化 O3 浓度的方法已商业化（Alphasense Ltd.，Essex，UK）：配置一对传感器，一个典型的氧化气体传感器，可响应 O3 和 NO2（型号 OX-B431），另一个类似的传感器可过滤 O3，仅响应 NO2（型号 NO2-B43F）。通过配对两个传感器，可以计算出 O3 浓度。我们仅使用 NO2 和 O3 校准了三个 NO2-B43F 传感器和三个 OX-B431 传感器的样品，并在 0–1.0 ppm NO2 和 0–125 ppb O3 范围内进行了混合物实验，以评估配对传感器量化混合物中 NO2 和 O3 浓度的能力。尽管每种类型的三个传感器样本之间的响应斜率差异高达 37%，但 NO2-B43F 传感器对 NO2 的个体响应以及 OX-B431 传感器对 NO2 和 O3 的个体响应在所研究的浓度范围内呈高度线性（R2≥ 0.99）。 NO2-B43F 传感器对 O3 气体的响应极小，响应斜率在统计上不显着。在 NO2 和 O3 的混合物中，NO2 的定量通常准确，高估高达 29%，而 O3 通常被低估高达 187%。我们在 4 天的实验中观察到传感器基线的变化相当于 34ppb O3，从而催生了通过基线校正传感器信号来计算浓度的替代方法。基线校正方法导致 NO2 的低估高达 44%，O3 的低估减少高达 107%。随着 NO2 信号与 O3 信号之比的增加，两种计算气体浓度的方法都会逐渐低估 O3 浓度。我们的结果表明，配对的 NO2-B43F 和 OX-B431 传感器可以对混合物中的 NO2 和 O3 进行定量，但 O3 浓度估计的准确度和精度低于 NO2 的估计。
Typical low-cost electrochemical sensors for ozone (O3) are also highly responsive to nitrogen dioxide (NO2). Consequently, a single sensor’s response to O3is indistinguishable from its response to NO2. Recently, a method for quantifying O3concentrations became commercially available (Alphasense Ltd., Essex, UK): collocating a pair of sensors, a typical oxidative gas sensor that responds to both O3and NO2(model OX-B431) and a second similar sensor that filters O3and responds only to NO2(model NO2-B43F). By pairing the two sensors, O3concentrations can be calculated. We calibrated samples of three NO2-B43F sensors and three OX-B431 sensors with NO2and O3exclusively and conducted mixture experiments over a range of 0–1.0 ppm NO2and 0–125 ppb O3to evaluate the ability of the paired sensors to quantify NO2and O3concentrations in mixture. Although the slopes of the response among our samples of three sensors of each type varied by as much as 37%, the individual response of the NO2-B43F sensors to NO2and OX-B431 sensors to NO2and O3were highly linear over the concentrations studied (R2≥ 0.99). The NO2-B43F sensors responded minimally to O3gas with statistically non-significant slopes of response. In mixtures of NO2and O3, quantification of NO2was generally accurate with overestimates up to 29%, compared to O3, which was generally underestimated by as much as 187%. We observed changes in sensor baseline over 4 days of experiments equivalent to 34 ppb O3, prompting an alternate method of calculating concentrations by baseline-correcting sensor signal. The baseline-correction method resulted in underestimates of NO2up to 44% and decreases in the underestimation of O3up to 107% for O3. Both methods for calculating gas concentrations progressively underestimated O3concentrations as the ratio of NO2signal to O3signal increased. Our results suggest that paired NO2-B43F and OX-B431 sensors permit quantification of NO2and O3in mixture, but that O3concentration estimates are less accurate and precise than those for NO2.