Continuous monitoring of aerosols and gases in ambient air

Ambient air quality is critical for our health and the environment.

MARGA is a fully autonomous sampling and measurement system that continuously measures the gases and aerosol components that might have a direct effect on air quality.

MARGA air monitoring system

Key features

  • Gases measured: HCl, HNO3, HNO2, SO2, NH3
  • Aerosol ions measured: CL-, NO3-, SO42-, NH4+, K+, Ca2+, Mg2+
  • Time resolution of 1 hour, with full results available 1 hour after sample collection
  • Single software controls sampling and analysis and displays full diagnostic information.
  • Measurement by ion chromatography with internal standard eliminates calibration.

Advanced sampling system for accurate results

First, water-soluble gases are absorbed in a Wet Rotating Denuder device and then the water-soluble ions in the aerosols are extracted in a Steam-Jet Aerosol Collector.

The gas and aerosol samples are then analyzed by ion chromatography. A Flow Control Box (FCB) ensures a precise volume of air is flowing through the Sample Box each hour.

Sampling system of the MARGA analyzer for aerosols and gases

Unattended measurement of samples collected

Two ion chromatographs work fully automatically to analyze the collected gas and aerosol samples.

An internal standard is added during the measurement for a self-calibration and for an instant check on the performance of the column. The intuitive software records all data with validation indicators for results you can trust and report with confidence.

Ion chromatographs in the MARGA analyzer for aerosols and gases

Completely autonomous operation 24/7

MARGA is designed for monitoring in remote locations but never far from home – using a direct Internet connection. Therefore, its performance can be remotely measured, adjustments can be made, and results can be downloaded at any time.

An uninterrupted power supply (UPS) ensures operation during power cuts with automatic restart after longer power failures.

Aerosol and gas monitoring in ambient air with the MARGA system

Accepted worldwide

MARGA was developed by Metrohm Process Analytics in cooperation with the Energy research Centre of the Netherlands (ECN) and the U.S. EPA. Furthermore, it has been verified by the U.S. EPA Environmental Technology Verification Program (ETV). It is used worldwide, contributing data to many environmental monitoring programs and studies.

From China to Finland and Mexico, it is known throughout the scientific community as a proven method for monitoring ambient air quality – and thus helping to protect our health and the environment.

ETV logo


MARGA excels by its capability of automated data acquisition as well as calculating and storing of results.
Fei Li, researcher at the aerosol ingredient laboratory, Institute of Tropical and Marine Meteorology, Guangzhou