Modification of Giano for Particulate Matter and Gaseous PAH Sampling
Introduction to Giano
Ravebo B.V., in collaboration with Dado Lab S.r.l., has implemented modifications to an existing product called “Giano.” The Giano is a sampling unit for sequential particulate matter sampling in ambient air in accordance with NEN-EN12341.
The reason for this was a public tender request for the delivery of such a unit (PM10 sequential sampling system), but also suitable for the additional sampling of gaseous PAHs (Polycyclic Aromatic Hydrocarbons). Ultimately, these units are used to determine the PAH concentration in ambient air. PAHs occur both particle-bound and in gaseous form.
Development by Dado Lab
Dado Lab developed a sequential sampling system. The basis is a multifunctional processor with a filter switching system. Sampling schedules can be programmed and measurement data output. This processor with filter switch can be mounted in a 19” rack system. The processor can control two sampling lines and two filter switch systems (simultaneously); for example, it is possible to perform PM10 and PM2.5 sampling at the same time. Each line’s filter system holds up to 21 filters. For stand-alone applications, the system is available built into a suitable outdoor enclosure with sampling pump(s). The Giano model is a system equipped with one sampling line and one filter switch system.
Modifications and Requirements
Several modifications were made to the standard Giano PMx sequential sampler to meet the specified requirements. As mentioned, for the sampling of gaseous PAHs, an absorption cartridge must be added after the filter. In this specific case, the use of a single cartridge is allowed since an average concentration over several days is determined. However, a requirement is that the storage temperature for both the sampled filters and the absorption cartridge must not exceed 23°C. To guarantee this, air conditioning is applied. Condensation can occur after the sampled filter due to high outdoor temperatures and humidity. Therefore, a condensate trap is included before the absorption cartridge to ensure that only dry gas passes through the absorption material.
Since samples are collected over an extended period (14 days), and it is difficult to predict how high the resistance of the absorption cartridge may become over time, an extra powerful high-capacity pump is used.
Another requirement was full correction for the actual sampling flow rate of 2.3 m3/h. This not only includes the proper correction for temperature and pressure but also for variations in relative humidity. Because the software and firmware of DadoLab instruments are fully developed in-house, this feature was quickly implemented in the firmware. Additionally, the unit is equipped with an interface for sensors measuring wind speed and wind direction. This can provide valuable extra information for ambient air sampling. The firmware also supports programming sampling schedules based on certain wind directions.