Instrumentation

We require measurement instruments for our research work. Some of these can simply be purchased, but this is often not the case. If so, we develop the required instrument ourselves.  

We have already been doing this since the 1970s, when “acid rain” was a topical issue. However, no reliable detection systems for monitoring air pollution were available. Particles and gaseous pollutants also had to be measured separately in many cases. ECN therefore developed the “wet denuder” to capture gaseous components in a water stream (without capturing particulates). Particulate matter was then captured with filters. Initially, the water samples were collected and analysed in the laboratory. Nowadays, the analysis equipment also forms part of field instruments and therefore produces numerical data continuously. This information is sent to the user via telephone or the Internet.  

Since around 2000, we have replaced the filters used to capture particulates with a “Steam Jet Aerosol Collector” (SJAC) for a number of analyses. This collects the particulates (therefore not gaseous pollutants) in a water stream that is supplied directly to the analysis equipment that forms part of the field instrument. It is therefore no longer necessary to retrieve filters, and aerosol-related data is immediately available.  

From the 1980s onwards, ammonia attracted greater attention because it appeared to contribute to acidification and the formation of particulate matter. It emerged that it was important to be able to determine at measurement locations how many micrograms of ammonia per square meter per hour were emitted into the atmosphere or absorbed from it. We also developed the equipment required to this end. It measures concentrations and wind speeds at various altitudes.  

Not all elements of particulate matter are water-soluble. The most important of these is soot. Soot poses a risk to public safety and causes the additional absorption of sunlight, which contributes to global warming. We have developed a separate measurement instrument for soot that also produces and sends numerical data constantly.  

Finally, we are busy developing methods to monitor concentrations of heavy metals and oxidising elements in particulate matter with the help of field measuring instruments.