Proficiency Testing (ISO/IEC 17043) – Determination of particulate matter (dust) – manual gravimetric method

More information you can find on www.alme.cz/

Downloads

Proficiency Testing

Proficiency testing is a evaluation of participant performance against preestablished criteria by means of interlaboratory comparisons. The need for ongoing confidence in laboratory performance is not only esential for laboratories and their customers but also for other interested parties, such as regulators, laboratory accreditation bodies and other organizations that specify requirements for laboratories.

Český institut pro akreditaci (ČIA, www.cai.cz) – the Czech Accreditation Institute (CAI) – in connection with laboratory Proficiency Testing (PT) by means of interlaboratory comparison in conformity with EN ISO/IEC 17043 and with MPA 30–03–12 par. 4 issued Certificate of Accreditation no. 376/2015 for Association of Laboratories for Emission Measuring (Asociace laboratoří pro měření emisí – ALME, www.alme.cz) to provide of proficiency testing also for method: ALME 06/12 Determination of particulate matter mass flow in flowing air mass.

The proficiency testing for determination of particulate matter mass flow is performed every year since 2009 on a dust testing train for particulate matter determination which is operated at VSB – Technical University Ostrava in the Energy Research Center testing room.

How does the dust testing train work?

Preparation of a concentrated aerodispersive mixture is ensured by a vibration batcher which spills a known amount of dust into a funnel from which the air and dust mixture is transported to an ejector. The ejector sucks-in the batched dust with air and mixing of this mixture with ejector jet air occurs in a diffuser. Follow-up, this mixture is transported by way of f20 mm pipeline through a conical mixing piece (perforated sheet) to an inlet into the testing train sampling section which is formed by f 313 mm vertical pipeline of c. 7 m length. On the vertical sampling section, there are two locations enabling to realize a representative air mass sample take-off for determination of the mean concentration of particulate matter and their mass flow. Further, the air mass is lead into a filtration device where a substantial part of batched dust is captured. The filtration device is subsequently connected with an exhausting fan which represents a source of suction for the dust testing train. The particulate matter mass flow reference value is determined on the basis of the batched dust weighed amount and batching time. The particulate matter mean concentration reference value is determined from the particulate matter mass flow and air mass volume flow in the dust testing train. Air mass volume flow is determined by the Venturi tube which is positioned before the filtration device. Flow rate is controlled with the help of a frequency converter which alters the exhausting fan rotational speed.

What is the dust testing train able to do?

The dust testing train allows preparation of the reference („veritable“) value of the following factors in the vertical pipeline:

Particulate matter mass flow (25–2500 g/h)
Particulate matter mean concentration (5 up to 500 mg/m3 – at 101325 Pa, 0°C)
Air mass mean velocity (5–20 m/s)

Proficiency testing performed so far

Three years of proficiency testing were organized and participants were from the Czech and Slovak Republic.

2009 – number of participants – 47
2010 – number of participants – 37
2011 – number of participants – 27
2012 – number of participants – 26
2013 – number of participants – 28
2014 – number of participants – 30

Evaluated values:

Particulate matter mass flow in the dust train
Particulate matter mean concentration in the dust train
Air flow mean velocity in the dust train
Air mass volume flow in the dust train

Evaluation was carried out on the basis of determination of the best Z scores for the particular given parameters. That measuring group was successful, which achieved Z-score value ≤ |2| at least once of three measurements for the given observed parameter. Successfulness of the measuring groups for determination of particulate matter mass flow was as follows:

in 2009 – 91.5 %
in 2010 – 86.5 %

Other utilization of the dust testing train?

Except for the proficiency testing for particulate matter determination, the dust testing train can be used e.g. for the following spheres:

Verification of dust-meters functionality (calibration, sensibility to a kind, shape, size and colour of particulate matter)
Validation of devices for on-line determination of dust concentration –
Determination of filtration properties of materials for industrial filtration
Study of fractional separability of filtration materials – adding particulate matter counter to the train

Preparation of the required dust amount batching

Diluting and stirring the aerodispersive mixture

Determination of volume flow of air mass with dust, its subsequent cleaning and exhausting from the testing room.

The dust testing train with the known reference mass flow of dust with a possibility of manual air mass sampling (according to ISO 9096 or EN 13284–1) in two measuring profiles.