The DPM Cassette
SKC Diesel Particulate Matter Cassettes are designed for sampling in atmospheres where it is necessary to separate DPM from other respirable dust (such as coal dust). Single-use SKC DPM Cassettes are tamper-evident sealed to ensure sample integrity. Each streamlined plastic cassette comprises an impactor plate, impaction substrate, and two heat-treated quartz filters. The impactor screens out respirable particles > 1 µm. Particles less than 1 µm are collected on the first filter and the second filter serves as a dynamic blank for correction of absorbed organic carbon. Samples are analyzed for organic and elemental carbon content using a highly sensitive Evolved Gas Analysis (EGA) technique with thermal-optical analyzer as specified in NIOSH Method 5040.
The DPM Advantage
Collection of submicron diesel particles without interference of coal-source elemental carbon. Impactor screens out interfering coal dust.
Low carbon background filters assure accurate results.
Single-use cassettes are tamper-evident sealed to ensure sample integrity.
Uses a standard personal constant flow pump. Flow rates of 1.7 L/min and 2 L/min provide optimum collection. Use a standard constant flow sample pump such as the SKC AirChek or Universal XR Series.
Meets specifications of NIOSH 5040 for the analysis of elemental carbon (EC) to determine total carbon (organic and elemental) in a sample. Total carbon represents more than 80% of diesel particulate emissions. Compared to gravimetric methods, NIOSH 5040 is more sensitive and specific for EC.
The DPM Sampling Train
The SKC DPM Cassette is used with a sample pump capable of a flow rate of 1.7 or 2 L/min such as the AirChek or Universal XR Series. A respirable cyclone may be added to the train in sampling situations where carbonate or other larger particles are present that could clog the cassette impactor. SKC offers the GS-1 Single-inlet Cyclone for use with DPM Cassettes.
|
The GS-1 Single-inlet Cyclone
The GS-1 Cyclone is a single-inlet cyclone that provides performance equivalent to the 10-mm nylon cyclone. The GS-1 Cyclone has the added advantage of conductive plastic construction. This material eliminates the electrostatic effects experienced when using the non-conductive nylon 10-mm nylon cyclone and is safe for use in underground mines. The GS-1 Cyclone is designed for use with the SKC DPM Cassette and for respirable dust sampling.
A cyclone should be used in settings where carbonate particles or larger particulate that can clog the impactor are likely to be sampled.
|
 |
| |
|
Cassette Without Impactor for NIOSH 5040
SKC Also offers preloaded cassettes without impactors (Cat. No. 225-401) that meet NIOSH 5040 specifications for sampling DPM. When it is not necessary to separate DPM from other respirable particles, such as coal dust, perform more economical sampling by using the Cat. No. 225-401 preloaded cassettes. Each cassette contains a NIOSH-specified heat-treated, binder-free quartz filter and cellulose support pad. |
 |
| |
|
Filter Cassette/Cyclone Holder Accessory
This lightweight holder accommodates either a DPM Cassette or other filter cassettes with or without a cyclone. The holder conveniently clips to a worker's collar. It is required when using the DPM Cassette with the GS-1 Cyclone. |
 |
Elemental Carbon Analysis
NIOSH 5040 recommends analysis of elemental carbon to quantitatively determinethe total carbon (organic and elemental) in a sample. Total carbon representsmore than 80% of diesel particulate emissions. When compared to gravimetric methods,NIOSH 5040 for Elemental Carbon Analysis is morespecific and sensitive.
Custom Cassettes with Integral Impactors
ONLY from SKC!
SKC will manufacture custom-designed sampling cassettes in the DPM cassette housing using filter media and impactors with your specified cut-points and flow rates. Contact SKC to discuss your unique sampling requirements. |
 |
Reference:
Sampling Results of the Improved SKC Diesel Particulate Matter Cassette. By James D. Noll, Robert J. Timko, Linda McWilliams, Peter Hall, and Robert A. Haney. J Occup Environ Hyg. 2005 Jan;2(1):29-37.
