ILMARI

The ILMARI chamber has been designed for performing aging studies of emissions from different sources in atmospherically relevant conditions. The suite of sources includes biomass burning appliances and vehicles mounted on a chassis dynamometer.

The chamber is a batch reactor where the oxidizing environment, humidity, temperature, the amount of initial seed, and UV conditions are controlled. The chamber is located in an air-conditioned and temperature-controlled enclosure and it consists of a 29 m3 TeflonTM FEP bag mounted in a frame which has a movable top and a counterweight system to ensure the pressure control over the experiments. Normally, the chamber is kept at an overpressure of a few Pa, in order to minimize the inward flow of contaminants. The measured half-life of aerosol particles in the chamber is at least 8 hours (size-dependent).

In the emission experiments, the diluted emissions from combustion sources or selected precursor organics are injected to the chamber so that the wanted concentrations are achieved. 

Photochemical reactions are initiated by ultraviolet radiation produced by blacklight lamps located in the sides of the chamber. Two types of lamps, with spectra centered at 350 nm and 340 nm, are used to produce radiation spectrum that corresponds the radiation conditions comparable to local atmospheric conditions. The chamber enclosure is coated with reflective aluminium blanket to maximize the irradiance in the chamber and to ensure an equal illumination. When dark aging is desired, oxidants, such as ozone, can be injected into the chamber. The ozone production capacity in ILMARI is high enough to achieve also ozone concentrations of several ppm, if needed, in the experiments and cleaning procedure. 

Between experiments the chamber is flushed with clean air produced by an AADCO 737-250 air purifier with methane reactors and humidified with ultrapure deionized water to the wanted humidity. The temperature and relative humidity are measured in the middle of the chamber and gaseous components, such as ozone, oxides of nitrogen, sulphur dioxide, and carbon dioxide, are monitored continuously.

ILMARI is equipped with state-of-the-art particle and gas analysis systems. Particle size distributions can be measured online using Differential Mobility Analysers (DMA), the Electrical Low Pressure Impactors (ELPI) and the Fast Mobility Particle Sizer (FMPS). For online particle measurements condensation particle counters (CPC), Tapered Element Oscillation Microbalance (TEOM) and Nanoparticle Surface Area Monitor (NSAM) are available for online particle number, mass and surface area measurements, respectively.

Particle size-resolved chemical composition is analysed with Soot Particle Aerosol Mass Spectrometer (SP-AMS). Gas compounds are analysed using several single component gas analysers, an FTIR multicomponent analyzer, as well as with mass spectrometers including Proton Transfer Reaction – Mass Spectrometry  (PTR-MS) and atmospheric pressure chemical ionization mass spectrometry (API-ToF-MS).

Aerosol optical properties (light scattering and absorption) are measured with a nephelometer and an aethalometer, respectively.

Further aerosol analysis systems include the Aerosol Particle Mass Monitor (APM), Cloud Condensation Nuclei counter (CCNc), Hygroscopic and Volatility Tandem Differential Analyzers (HTDMA, VTDMA), and a Spectrometer for Ice Nuclei (SPIN).

Off-line analyses of particles and gases are carried out from filters, impactior substrates and absorbent tubes. From the collected particulate sample metals, water soluble ions, PAHs, organic carbon (OC) and element carbon (EC) can be analysed. Also samples for electron microscopy using SEM and TEM with EDS elemental analyses are performed.

Features that make it rare in the world:
- Connection to a versatile set of emission sources
- Connection to an on-line exposure system for living cells, for health effect studies
- Quality and versatility of the instrumentation
- Considerably long half-life of aerosol particles

The services offered by the infrastructure include:

- Access to the full equipment of the ILMARI chamber

-Technical assistance by experienced aerosol physicists and laboratory engineers

- Personnel to operate the full ILMARI facility

- Copy of all the level 0 data at the end of the campaign

- Data treatment up to level 1 when requested

- Daytime access to the lab spaces if requested

- In-campus accommodation

- Guest office and internet access for visitors

- Support for ordering chemicals and consumables

Between 2 and 4 weeks plus the preparatory phase. A typical work includes:

- one or two weeks preparation by UEF personnel to carefully prepare the experiments (latest protocol adjustments, connection and preparation of emission sources and measurement instruments, and training on the use of the chamber and on the main services). NB! The infirmation about the campaign timing must be submitted to UEF at least 6 months before the actual measurement campaign, to confirm the availability of the ILMARI facility.

- Experiments (1 experiment per day, including week-ends if needed)

- Dynamic debriefing and adjustment of experiments during the measurement campaign, if needed

- a couple of days for debriefing and ase data formatting, saving and distributing among the users

- 1-2 weeks of data processing by UEF personnel for level 1 data availability

The ILMARI chamber is mainly used for research projects but it is also open to experiments conducted with companies.

The ILMARI chamber is a collapsible bag made of Teflon FEP with a shape of a rectangular prism.

Dimensions: 3.5 m (L), 3.5 m (W), 2.4 m (H)

Volume: 29.4 m³

Surface area: 58.1 m²

Projected surface area: 8-12 m2

Surface-to-volume ratio: 2.0 m^-1

S/V ratio: 2 m^-1

JNO2 = 0-5.5e-3 s-1

Temperature, pressure, and RH range: The temperature in ILMARI chamber in irradiation experiments can be controlled between 20 and 40 degC and in dark experiments between 15 and 40 degC, although typically the experiments are done at 20 ± 1 degC. 

The pressure in the chamber is not controlled and is the prevailing atmospheric pressure plus the few pascals overpressure. 

The relative humidity in the chamber can be adjusted between 3 and 100 %RH but typical humidities are 3-5 %RH for dry experiments and 50%RH for humid experiments.

- Injection and sampling lines through the chamber floor.

- A maintenance hatch in the chamber floor for in-chamber access.

- The collapsible bag is attached to a movable top frame for pressure control.

- Blacklight lamps on two opposite sides of the chamber.

Spectrum for "340 nm" lamps:

Spectrum for "350 nm" lamps:

Spectrum for "365 nm" lamps: