Performance Evaluation of Low-Cost BTEX Sensors and Devices within the EURAMET Key-VOCs Project

Laurent Spinelle,Gertjan Kok,Tilman Sauerwald,Stefan Persijn,Michel Gerboles

doi:10.3390/proceedings1040425

Laurent Spinelle, Gertjan Kok + Show 3 more

Open Access

https://doi.org/10.3390/proceedings1040425

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Abstract

The KEY-VOCs project is a EURAMET joint research project focused on key Volatile Organic Compounds (VOCs) in air. One of its activities is the evaluation of sensors-based measurement systems. In Europe, the monitoring of benzene in ambient air is mandatory as set by the European Directive for air quality (AQD) [1]. This Directive states that the reference method of measurement shall consist of active or on-line sampling followed by gas chromatography [2]. These methods are time consuming, expensive to implement and not easily portable prohibiting more local estimation of the population exposure. However, the AQD allows using indicative measurements with higher uncertainty than those of the reference methods. Sensor systems are good candidates for indicative methods with the additional ability of near-to real-time measurements.

Highlights

Low-cost sensors are attracting more and more interest, as they would be able to provide a cheaper way to monitor air quality on a larger scale
volatile organic compounds (VOCs) in ambient air [4,5], the authors concluded that the current sensor technology is not yet able to measure the concentrations expected in ambient air and that they generally suffer from poor selectivity
Using the MACPoll Protocol of evaluation and calibration of low-cost gas sensors [6] which targeted low-costs sensors for inorganic gaseous, we present the evaluation of low-cost sensors and sensor based devices for benzene measurements

Summary

Introduction

Low-cost sensors are attracting more and more interest, as they would be able to provide a cheaper way to monitor air quality on a larger scale. If the current sensor technology can be considered efficient enough for inorganic gases such as CO, CO2 and to a lower scale O3 and NO2 [3], that is not the case for volatile organic compounds (VOCs) and in particular BTEX (Benzene, Toluene, Ethylbenzene and Xylene). The AQD defines as mandatory the monitoring of benzene in ambient air. It allows the use of indicative measurement methods but it requires the use of a selected method to meet a defined Data Quality Objective (DQO). This DQO is defined as the relative expanded uncertainty of measurement and it shall be assessed in the region of the limit value (LV) of 5 μg/m3 for the annual mean

Materials

Methodology and Results

Conclusions