Gravimetric dust measurement

from Wikipedia, the free encyclopedia

The gravimetric dust measurement , and gravimetry called, is a method for the determination of airborne particles and dust emissions . With this measuring method , dust is deposited on a filter and then weighed . Gravimetric dust measurement is used to calibrate automatic dust measuring devices. The systematic gravimetric dust measurement started in 1950; a standard was implemented in 1971.

Process description

In gravimetric dust measurement , the dust-laden gas is passed through a previously conditioned and weighed filter, whereby the dust contained in the gas is deposited on the filter. The applied filter surface is then dried and weighed. The mass of dust deposited on the filter in relation to the recorded gas volume gives the average dust concentration of the gas.

Gravimetric dust measurement only records particles that are deposited on the filter. That is why the achievable degree of separation of the filter materials used for selected test aerosols must be well over 99%.

Gravimetric dust measurement can be used for both emission and immission measurements. Measurements at the workplace are also possible. In comparison to emission measurements, immission measurements usually require a longer period of time until a sufficiently large amount of dust has collected on the filter surface. As a rule, the collection time for immission measurements is 24 hours.

Sources of error

Possible sources of error are weighing errors and dust deposits outside the filter. Leakages in the measuring equipment can also lead to incorrect measuring results.

In the case of emission measurements, non- isokinetic sampling can lead to errors if too few or too many particles are deposited on the filter. Dust can also be deposited in the pipeline leading to the measuring device during extractive sampling.

literature

  • VDI 2066 sheet 1: 2006-11 measurement of particles; Dust measurements in flowing gases; Gravimetric determination of dust load (Particulate matter measurement; Dust measurement in flowing gases; Gravimetric determination of dust load). Beuth Verlag, Berlin. ( Summary and table of contents online )

Individual evidence

  1. ^ A b c Franz Joseph Dreyhaupt (Ed.): VDI-Lexikon Umwelttechnik. VDI-Verlag Düsseldorf 1994, ISBN 3-18-400891-6 , p. 586.
  2. ^ Karlheinz Guldner, Dirk Dahmann, Markus Mattenklott, H.-H. Fricke, Othmar Steinig, Johannes Böhm: Development of conversion factors for results of early gravimetric dust measurements. In: Hazardous substances - cleanliness. Air . 71, No. 5, 2011, ISSN  0949-8036 , pp. 191-198.
  3. ↑ VDI 2463 sheet 1: 1999-11 measurement of particles; Gravimetric determination of the mass concentration of particles in the outside air; Basics (Particulate matter measurement; Gravimetric determination of mass concentration of suspended particulate matter in ambient air; General principles). Beuth Verlag, Berlin, p. 11.
  4. ↑ VDI 2066 sheet 1: 2006-11 measurement of particles; Dust measurements in flowing gases; Gravimetric determination of dust load (Particulate matter measurement; Dust measurement in flowing gases; Gravimetric determination of dust load). Beuth Verlag, Berlin, p. 36.
  5. ↑ Heinrich Thürmer, Horst Bytel, Erhardt Gierke: The transition from the Johannesburg Convention to DIN EN 481 - gravimetric comparison measurements at workplaces. In: Hazardous substances - cleanliness. Air. 62, No. 11/12, 2002, ISSN  0949-8036 , pp. 447-454.
  6. ↑ VDI 2463 sheet 1: 1999-11 measurement of particles; Gravimetric determination of the mass concentration of particles in the outside air; Basics (Particulate matter measurement; Gravimetric determination of mass concentration of suspended particulate matter in ambient air; General principles). Beuth Verlag, Berlin, p. 11.
  7. ↑ Christoph Sager, Frank Schmidt, Klaus Gerhard Schmidt: Investigations on particle deposition in sampling lines due to various transport mechanisms. In: Hazardous substances - cleanliness. Air. 61, No. 5, 2001, ISSN  0949-8036 , pp. 207-211.