# Toward an Event-Based and Quality-Assured Air Sampling: A Portable System for Sensing and Sampling Volatile Organic Compounds

## TL;DR

This paper introduces a portable system that combines real-time air monitoring with quality-assured sampling of volatile organic compounds.

## Contribution

The novel contribution is a modular, portable system integrating gas sensors and active sampling for reliable air quality data.

## Key findings

- The system enables real-time monitoring and active sampling of air pollutants using a gas sensor array and sorbent tubes.
- Remote access to sensor and sampler data helps identify malfunctions during long-term measurements.
- The system is powered by a lightweight battery that can be charged using solar panels.

## Abstract

Sensors for monitoring
volatile organic compounds are commonly
employed for air quality control in indoor and outdoor environment.
They provide data with high temporal and spatial resolution. Although
these sensors can detect possible concentration changes very quickly,
they do not provide any information about the composition of air pollutants.
Furthermore, the measurements are strongly influenced by gaseous interfering
compounds and meteorological conditions. It is necessary to carry
out measurements in the laboratory for reliable and credible data.
The adsorptive enrichment of air samples on solid adsorbents is the
most commonly used method for taking air samples. We wanted to combine
the advantages of both approaches. Therefore, a portable modular sensor
and multitube sequential sampling system has been developed. It combines
real-time online monitoring of ambient air using a gas sensor array
and quality-assured active sampling. The sensor module consists of
an optimized 3D-printed sensor chamber where up to 4 gas sensors can
be integrated. The sampler module was equipped with up to 32 commercially
available sorbent tubes. The inlet pressure of the mass flow controller
and temperature are permanently recorded, allowing the detection of
a leakage or tube clogging during the sampling procedure. The remote
access to the data from both the sensors and the sampler parameters
allows the identification of possible malfunctions, which limits the
necessary presence of an operator during long-term measurements. The
power supply is realized with a lightweight battery, which can be
charged by solar panels.