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Cyclone Samplers for Respirable Dust
Operating Instructions
This instruction sheet covers the following sampler models:
• 225-69 Cyclone sampler with re-usable cassette for 25mm diameter filter
• 225-69-37 Cyclone sampler with re-usable cassette for 37mm diameter filter
Introduction
The cyclone sampler is designed for dust (aerosol) sampling to the respirable convention as defined in
standard EN481:1993, using HSE method MDHS 14/3 “General methods for sampling and gravimetric
analysis of respirable and inhalable dust”.
It is highly recommended to obtain and read the document MDHS 14/3, available from the HSE website
www.hse.gov.uk, before carrying out any sampling using the cyclone sampler.
Design flow rate is 2.2 l/min, giving a 50% sampling efficiency (cut point) at 4.0µm (micron) particle size.
The SKC plastic cyclone is manufactured from conductive plastic which dissipates electrical charges to the
surrounding atmosphere and prevents static interference on the collection of the dust particles.
The filter is held within a re-usable plastic cassette, which is supplied complete with a metal filter support
grid and a sealing clip to prevent contamination of the sample during transport for laboratory analysis.
For detailed instructions on air sampling in general and use of the cyclone sampler in particular refer to
SKC’s 224-G1 Step by Step Guide to Air Sampling.
Preparing the Cyclone Sampler for Use
The following instructions give basic details on how to prepare for sampling by gravimetric analysis
according to MDHS 14/3.
Select two filters from the same box or batch. One filter is used whilst calibrating the sample flow rate and
is then discarded, and the other is pre-weighed to carry out the actual sample.
It is recommended to wear powder free gloves and to use tweezers when handling filters in order to prevent
contamination prior to taking the sample.
Loading the cassette
Ensure that the cyclone sampler components are cleaned of any contamination, using a detergent solution.
Allow the components to dry fully before use.
Place the top part of the cassette (labelled “TOP”) upside
down on a flat surface.
Place the metal filter support grid into the top part of the
cassette. Place the filter to be used for calibration onto
the support grid.
Fit the bottom part of the cassette onto the top part and
press down gently on the edges of the bottom part to
close the cassette.
Avoid exerting undue pressure on the filter. The closure
is intentionally stiff to avoid accidental opening, and to
ensure a leak tight fit.
Fitting the cassette into the cyclone sampler
Referring to Figure 2 on page 2, ensure that the large O
ring is fitted to the sampler body beneath the sampler
insert and the small O ring is fitted over the short tube in
the middle of the insert.
Fit the assembled cassette into the cyclone insert with
the cassette top upwards.
007-04-001 Issue C January 2009
Figure 1
Cassette bottom
Filter
Filter support grid
Cassette top
Page 1
Check that the thin O ring is fitted into the recess in the underside
of the sampler top. Place the sampler top on the cassette. Fit the
retaining ring over the sampler top and screw down firmly to secure
the cassette within the sampler and seal the cassette inlet and outlet.
Ensure that the grit pot is securely fitted over the ridge around the
bottom of the sampler body.
Flow Calibration
Connect the inlet hosetail of the sample pump to the air outlet of the
cyclone sampler with a length of flexible tubing. Connect the flow
calibration device (such as a rotameter or Defender primary calibrator)
to the air inlet of the cyclone sampler using a second length of flexible
tubing.
Calibrate the sample flow rate to 2.2 l/min.
Disconnect the tubing from the cyclone sampler inlet and outlet.
Remove the cassette from the cyclone sampler.
Hold the cassette upside down and prise the two halves apart using
the side tab. Remove and discard the calibration filter. Place the preweighed filter to be used for the sample, onto the filter support grid and
re-assemble the cassette. Fit the cassette into the cyclone sampler.
Quickly re-check the flow rate and make any final adjustments. Switch
the sample pump off.
The cyclone sampler is now ready for sampling.
After Sampling
Away from the sample location quickly check the sample flow rate,
then disconnect the tubing from the cyclone sampler air inlet and
outlet.
Carefully remove the cassette from the cyclone sampler and split the
two parts of the cassette apart.
Post Weighing the Filter
Carefully lift the filter out of the cassette using tweezers. Post weigh
the filter.
The difference between the pre and post weights will give the
respirable sample.
Transportation
If further analysis is required, prepare the sample for transportation to
the laboratory by carefully placing the filter back in the cassette, and
fitting the yellow, U shaped sealing clip over the cassette inlet and
outlet holes. Use of the sealing clip prevents unwanted ingress or loss
of contaminant during transport. Alternatively, a 225-67 filter transport
cassette can be used, freeing the filter cassette for immediate re-use.
Figure 3
Figure 2
Retaining
ring
Sampler
top
Air outlet
O ring
Filter
cassette
O ring
Sampler
insert
O ring
Spring
clip
Sampler
body
Air inlet
Grit pot
SKC Limited 11 Sunrise Park, Higher Shaftesbury Road, Blandford Forum, Dorset DT11 8ST United Kingdom
007-04-001 Issue C January 2009
T: +44 (0) 1258 480188 F: +44 (0) 1258 480184 E: info@skcltd.com W: www.skcltd.com
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