A UV lamp reveals material that is green- and red-fluorescent.

Chemical dyes that react to gases are being researched in the laboratory at BAM. Dr. Jürgen Bartelmeß reveals the fluorescence effect using a UV lamp.

Source: BAM/Thomas Köhler

Germany emitted 671,000 tons of ammonia in 2013 – more than is permitted by the EU National Emission Ceilings Directive, or NEC. In fact Germany's permitted emissions of significantly environmentally-damaging gas created in factory farming are set at a maximum of 550,000 tonnes. The European Union is striving to achieve lower maximum values over the next few years.

Sensors with greater sensitivity now required

In order to reduce the emission of ammonia in the long term, the specific reasons and sources for high emissions need to be determined and countermeasures must be developed. Sensors that are better able to measure ammonia in the air at even lower concentrations are an essential tool here. More specifically, sensors need to be able to measure one molecule of ammonia in 1 billion molecules of air.

In the KonSens project (communicating sensor systems for component and environmental monitoring), a team around Dr.-Ing. Matthias Bartholmai is working on sensors that are able to achieve this. Fluorescence-based sensors use the specific light emission of a dye. If the gas to be measured comes into contact with the dye, the light emission changes and is detected by the sensor.

The scientists at BAM are researching the use of these fluorescence-based sensors to measure not only environmentally-damaging gases such as ammonia but also hydrogen sulphide and ozone. The objective is to be better able to measure different gases at even lower concentrations than previously.

A BAM employee inserts a sample with fluorescence material into an analysis device

Dr. Jürgen Bartelmeß with the fluorescence spectrometer for analysing samples: the materials produced in the laboratory are used in gas sensors.

Source: BAM/Thomas Köhler

Efficient measurement through mobile use

BAM is not only working on the sensors' sensitivity but also on effective and customised ways of using them. The intention is to make the sensors smaller and more mobile, so that they can also be integrated into a carrier platform – for example a flight platform. Measurements could then be remote-controlled when necessary. The KonSens project is therefore contributing to enabling more accurate investigation of wider applications in future, whilst also better isolating the causes of gas emissions.