APPENDIX 2 - DANETV

opløsningsmiddelsammensætningen i gassen med henblik på at beregne en resulterende
responsfaktor og en resulterende omregningsfaktor.
Ranges: 0 - 30, 0 - 300, 0 – 3.000, 0 – 30.000, 0 – 300.000 ppm C
Limit of detection: 1 mg C/m³
Uncertainty: 5 % of measured value (95% confidense interval).
FORCE Technology method: EM-12-01
Reference/standard: EN 12619, EN 13526, VDI 3481 bl.3
ELPI measuring particle number and size distribution
The ELPI (Electrical Low Pressure Impactor) sampling technique is a real time measurement of
the number concentration and size distribution through 12 particle size intervals (from 7nm to
10,000 nm). Particles are collected from the submicron range (from 30 nm) on 11 individual
substrates according to their aerodynamic size. The ELPI makes a real-time measurement of
each impactor stage by charging the particles before the impactor, and by counting the number
of particles collected at each stage. The mass concentration can be calculated assuming a unit
density, e.g. 1 g/cm³, for all particles.
When measuring high concentrations of particles, a dilution can be necessary. Sampling can be
performed through a dilution system comprising of a two-step dilution (dilution factor
approximately 1:100). Dry, HEPA filtered pressurized air is added as dilution air to the diluters.
The actual dilution ratio can be measured by means of propane gas and a flame ionization
detector. The diluted gas will reached a temperature slightly above ambient before the inlet of
the ELPI instrument.
The effect of non-isokinetic sampling is rather small for particles < 2500 nm, however isokinetic
sampling is sought. An out-stack pre-separator (cyclone) for separation of particles > 10 µm was
used.