SKC 225-380 User Manual

Operating Instructions

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SKC Re-usable Parallel Particle Impactors (PPI)

The patented† impaction-based SKC Re-usable Parallel Particle
Impactor (PPI ) Samplers are designed to match precisely the
collection effi ciency curves for respirable and thoracic dust
specifi ed by ISO/CEN 7708:1995 and adopted by ACGIH,
CEN, and other occupational hygiene organizations. The
performance of the respirable PPI samplers also meets
the specifi cations in the 2013 OSHA Notice of Proposed
Rule Making (NPRM) for respirable crystalline silica. The
thoracic model meets the requirements of NIOSH Method
5524 for metalworking fl uids and compounds with ACGIH
thoracic TLV

®

s. Constructed of conductive aluminum, these
PPI Samplers may be re-used and off er a choice of fl ow rates
for maximum fl exibility in pump options, sample duration,
and contaminant concentration.

Performance Profi le

Sampling Rate: 2 L/min respirable or thoracic and 8 L/min

Sample Pump: • Universal or AirChek

• Leland Legacy for 8 L/min

Sample Time: Dependent on method used
Sample Media: 37-mm PVC fi lter, 5.0-μm pore size or

Impaction
Substrate: Four 3/8-in diameter pre-oiled porous plastic discs, limited shelf-life

Analysis: Gravimetric or chemical
Body Material: Conductive aluminum
Dimensions:

Height: 4.25 in (10.8 cm) - clip to exhaust
Diameter: 1.8 in (4.6 cm)
Depth: 1.2 in (3.0 cm)

Weight: 3.3 oz (93.6 gm)

respirable

®

Series for 2 L/min

37-mm PTFE fi lter,* 2.0-μm pore size (NIOSH 5524) or
37-mm MCE fi lter, 0.8-μm pore size
Use cellulose pad or stainless steel screen for support.

®

† U.S. Patent No. 7,073,402
* Back pressure on PTFE fi lters can vary within the same lot.

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Principle of Operation

Dust enters here

SKC Re-usable PPI Samplers are impaction-based
fi lter samplers that perform precise size-selection
for either thoracic or respirable dust, depending
on the model. PPI Samplers contain four small

Inlet plate

impactors in the inlet section of the device. Each
impactor features a unique 50% cut-point to target
a specifi c one-quarter segment of the ISO/CEN
curve resulting in a precise fi t along the entire
curve. A sample pump operating at 2 or 8 L/min
(2 L/min only for thoracic) pulls air through the
inlet nozzle of each impactor in the inlet plate.
Particles larger than each impactor’s 50% cut­point are scrubbed and retained by impaction

Impaction
substrates (4)

Standard 37-mm
collection fi lter
and support pad

onto the porous oiled impaction substrate
contained in each impactor. Smaller particles
continue to the standard 37-mm collection fi lter

Base plate with
exhaust to pump

for analysis. See www.skcinc.com/prod/225-380.
asp for performance graphs.

Media Preparation

Filters: Condition and weigh fi lters according to method used. Record the weight
as the pre-sample weight.

Impaction Substrate: Using an oiled impaction substrate reduces particle
bounce. Replacement pre-oiled disposable porous plastic discs are available as SKC Cat.

No. 225-388 (pk/200).

Inserting a Collection Filter into the PPI

The PPI will arrive already assembled. Disassemble it to
insert collection fi lter.

1. Unscrew and remove two screws that hold the inlet

plate to the base plate.

2. Li off inlet plate to expose impaction plate.

3. Li off impaction plate to expose base plate.

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4. Using forceps, insert a 37-mm support pad and a 37-mm collection fi lter into

the base plate.

Inserting Impaction Substrates into the PPI

1. Ensure a support and collection fi lter have been loaded into the base plate

(see Inserting a Collection Filter).

2. Using forceps, insert a pre-oiled impaction sub-

strate into each of the four indentations in the
impaction plate.

Impaction substrates have a smooth/shiny side and
a rough/dull side. For optimum particle capture
effi ciency, place substrate smooth/shiny-side down
in the impaction plate.

3. Align pins in inlet plate with holes in impaction

plate and press together.

Pins will allow impactor to be assembled one
way only.

4. Grip impaction plate and inlet plate together and

twist on base plate until screw holes are aligned.

5. Replace and tighten two screws to secure inlet plate

to base plate.

Technical Tidbits:

• Use forceps to carefully insert or remove impaction substrate and collection

fi lter. See Accessories for forceps.

• SKC recommends using new impaction substrates for each sample period.

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