Sampling
The following sampling systems are available at the GSA for sampling diesel engine emissions:
- SG10-2 with FSP10 (personal sampling)
- PM4-2 with fine dust head (stationary sampling)
Personal sampling is usually done with the GSA measuring devices SG10-2 and FSP10.
With a battery-operated pump, SG10-2, the air loaded with dust is drawn at a flow rate of 10 l/min with a performance of 600 l/h. We recommend an as long as possible measuring period, as a volume of 12 m³ is needed to be able to detect 1/10 of the limit value. In a cyclone, like the FSP-10, the coarse dust is separated in a collecting cup and the air still loaded with A-dust flows through a membrane filter, an annealed binder-free glass fibre filter or quartz fibre filter with 37 mm diameter, on which the dust is separated.
Site-specific sampling is carried out by means of a volume flow-controlled sampling device with IFA A-dust sampling system (PM4-2A) with a volume flow of 4 m³/h. We recommend a measuring period of at least 3 h in order to obtain a volume of 12 m³ to be able to detect 1/10 of the limit value at 0.05 mg/m³.
As the filter medium a binder-free glass fibre filter or quartz fibre filter with a diameter of 70 mm is used.
Analysis
- Coulomat 702 of the company Ströhlein
Preparation of the filters
The binder-free glass fibre filters are annealed in a muffle furnace at 500 °C for 12 hours to remove any organic residues. The quartz fibre filters are annealed in a muffle furnace at 650 °C for 12 hours or at 800 °C for 4 hours to remove any organic residues.
Analytical determination
By analysing in two sub-steps, a separate determination of the organic components (OC)and the remaining soot component as (EC) can be achieved. In sub-step one, the components that are vaporisable or volatile at 500 °C are passed over platinum / copper oxide in the nitrogen stream. The oxidisable carbon contained in the gas stream is converted to carbon dioxide. After completion of the first sub-step, the remaining carbon is burnt in oxygen at 650 °C or 800 °C over platinum or copper oxide and converted to carbon dioxide.
The determination limit is 0.06 mg absolute per component. A blank value is mandatory for this analysis.
Limit value
According to TRGS 900 the occupational exposure limit for diesel engine emissions with diesel soot particles, as EC (elemental carbon), is 0.05 mg/m³.
Activities involving exposure to diesel engine exhaust are classified as carcinogenic.
If the occupational exposure limit value for diesel soot particles is complied with, no acute or chronic effects on the health of employees are generally to be expected. Thus, if the occupational exposure limit for diesel soot particles is observed, the activity is generally not carcinogenic according to TRGS 906.