The Basics of Air Sampling Step-by-Step

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Transcript The Basics of Air Sampling Step-by-Step

ACTIVE AIR SAMPLING

FOR CONTAMINANTS IN THE WORKPLACE

Presented by

ACTIVE SAMPLING DEFINED

The collection of airborne contaminants using a mechanical device such as a pump to draw the air/contaminant mixture

into or through

the sampling device such as a sorbent tube, filter, impinger, or sample bag.

THREE KEY COMPONENTS FOR ALL ACTIVE SAMPLING

 A sampling pump Something to pull or push air  A calibrator (flowmeter) Something to indicate how much air has been pulled or pushed  The sampling media Something to pull or push the air through or into for analysis

U.S. GOVERNMENT METHODS SAMPLING IN THE WORKPLACE

 National Institute for Occupational Safety and Health (NIOSH)  Occupational Safety and Health Administration (OSHA)

NOTE ON SAMPLING METHODS

 OSHA does not mandate the sampling method to be used for compliance.  The employer has the obligation of selecting a method that meets the accuracy/precision requirements of the standard i.e. ± 25% of the true value.  NIOSH or OSHA methods are typically used in compliance sampling.

WEBSITES FOR GOV’T AGENCY METHODS

 NIOSH Methods http://www.cdc.gov/niosh/docs/2003-154/  OSHA Methods http://www.osha.gov/dts/sltc/methods/toc.

html

EXAMPLE: NIOSH METHOD

EXAMPLE: OSHA METHOD

HELP FROM SKC

SAMPLING GUIDE IN SKC CATALOG

 Lists all regulated chemicals  Includes : – – – – Agency Method Number Sampling Details such as Flow Rate, Time, Volume Analytical method Sample collection media and catalog number

SKC AIR SAMPLING GUIDE

SKC Chemical Fact Files @ www.skcinc.com Click Training or Sampling Help

TYPES OF ACTIVE SAMPLES

FOR VARIOUS EXPOSURE PERIODS

 Integrated samples -Contaminants are collected and concentrated over a period of time to obtain average exposure levels during the entire sampling period  Grab samples -Contaminants are collected into a device over a short interval of a few seconds or minutes to represent exposures at a given point in time .

SAMPLING PUMPS:

FLOWRATE OPTIONS

 GASES AND VAPORS are sampled at low flow rates to allow effective adsorption to occur onto the sorbent material.

 PARTICULATES are sampled at high flow rates so that airborne particles can be effectively trapped onto the filter material.

LOW FLOW PUMP: SKC POCKET PUMP

Flow range of 20-225 ml/min

HIGH FLOW PUMP WITH LOW FLOW OPTION

SKC AIRCHEK XR5000 Flow range of 5-5000 ml/min using either lithium-ion or alkaline batteries

SAMPLING PUMPS: CONSIDERATIONS FOR USE

 Constant Flow -Is there an internal mechanism to compensate for restrictions to flow?

 Electromagnetic Susceptibility -Is there shielding from RFI/EMI?

 Backpressure -What is the maximum pressure drop that the pump can handle?

PUMP CALIBRATORS

 Set and verify the flowrate of the pump to that required in the sampling method  Should be done before and after every sample  The average of the pre and post- flowrates is used in calculations of air volume

17 PUMP CALIBRATION:

A CRITICAL MEASUREMENT

 Purpose is to determine the volumetric flow rate that will pass through the sampling media during the time the sample is taken.

 The flowrate is used to calculate total air volume.

FLOW RATE

(ml/min or L/min) x

SAMPLE TIME

(min)

=AIR VOLUME

(ml or L)

TYPES OF CALIBRATORS

18 PRIMARY STANDARDS

involve the direct measurement of volume on the basis of the physical dimensions of an enclosed space which do not change over time.

SECONDARY STANDARDS

trace their calibration to primary standards and have shown to maintain their accuracy with reasonable handling and care in operation.

PRIMARY STANDARDS

 Soap bubble meters/Film flowmeters   Electronic bubble meters Electronic “near frictionless” piston meters

SOAP FILM FLOWMETERS

 Pump pulls air through a glass tube with volumetric indications.  The liquid film-

a soap bubble

is interposed into the flow path.

 The air flow causes the bubble to move from one volume mark to another.

 The travel time is measured with a stopwatch  By knowing the travel time and the tube volume, the flow rate can be calculated.

CALCULATION

Question: If it took 128 seconds for the bubble to travel a 500 ml volume, what is the flowrate?

500 ml X 60 sec = 234.4 ml/min 128 sec min

TECH TIPS ON CALIBRATION

 It is not necessary for the flowrate to be the exact flow specified in the method. Just be sure you know exactly what it is .  Take at least 3 flow measurements that agree within 5% and use the average of the readings as your flow rate measurement.  If pre-and post-averages differ by more than 5%, your sample is called into question.

CALCULATIONS

Given travel times for bubble : 128.2; 129.1; 128.7 seconds.

Average time : 128.7 seconds 128.7 X 0.95

= 122.2

128.7 X 1.05

= 135.1

All times are within ± 5% range of acceptability

ELECTRONIC BUBBLE METERS 24

 Work on the same principle as a manual film flowmeter  Infrared sensors electronically time the bubble  Microprocessor instantly calculates flow rate and displays it digitally

NEAR-FRICTIONLESS PISTON METERS 25

 The flow of the pump causes the piston inside a chamber to rise and fall.

 Photo-optic sensors sense the rise and fall of the piston.

 An electronic timer combine with a microprocessor to automatically measure travel time and calculate the flowrate.

26 NOTES ON ELECTRONIC CALIBRATORS

 Both the electronic bubble meter and the piston meters use the volume of a cylinder to calculate the flow rate.  Because of the fixed cell volume, these units are defined as primary standards by the manufacturer and are considered so by OSHA. They should be sent in for factory check annually or as needed.

TECH TIPS ON CALIBRATION

 Let your pumps run 5 minutes before calibration after removing them from the battery charger to let the flow stabilize.  The pump must be calibrated with representative sample media in line . Use a clean set of media to collect the sample in the field after calibration.

SORBENT TUBE SAMPLING TRAIN

TECH TIPS ON CALIBRATION

 When available, use a calibration adapter to attach the sampler to the calibrator.  Alternatively, use a calibration jar of a size to fit the sampler.

FILTER SAMPLING TRAIN WITH CALIBRATION ADAPTER

SECONDARY STANDARDS

 Rotameters  Internal flow sensor of an air sampling pump  Wet Test Meter  Dry Gas Meter

ROTAMETERS

 Air passes through a vertical tube with  a ball or float inside The flow of air upward through the tube causes the ball to stabilize at a certain point  The flow rate is determined by the position of the ball in relation to the scale on the tube  Affected by both temperature and pressure

ROTAMETERS: CONSIDERATIONS FOR USE

If the rotameter was originally calibrated with one end open to the atmosphere (i.e.

at atm. pressure) and you later use it for calibration in between the pump and media, the rotameter will indicate a lower flowrate.

CALCULATION FOR ROTAMETERS

new

= Q

ntp

[(760/P

new

) (T

new /

298)]

0.5

A rotameter was calibrated at NTP and measured a flow rate of 2 L/min. If the conditions changes to 30 C and 1.2 atmospheres, what should the new flow be?

Q new = 2 [760/(760 x 1.2)] [(273+30)/298]

0.5

= 1.84 L/min

PROPER CALIBRATION

ENSURES ACCURATE  Air Volumes  Measurement of exposure levels Flow Rate X Time=Air Volume Mass of contaminant/Air Volume=

SAMPLING MEDIA

ACTIVE SAMPLING OF GASES AND VAPORS

37 DEFINING GASES AND VAPORS

 A substance is considered a GAS if this is its normal physical state at room temp (25 o C) and one atm. (760 mm Hg) pressure (Example: Carbon monoxide)  If the substance is a liquid at normal temp and pressure, then the gaseous component in equilibrium with its liquid (or solid) state is called a VAPOR . (Example: Benzene)

SOLID SORBENTS

INTRODUCTION

    Most widely used media for gases/vapors Consist of small granules or beads

sorb the contaminant onto the surface Packed into tubes to collect various amounts and types of chemicals

SAMPLE COLLECTION

WITH SORBENT TUBES

 Most tubes have 2 sorbent sections.

 Breakthrough (sample loss) is indicated when contaminant levels on the backup section are ≥ 25% of the levels found on front sorbent section.

40 MORE ON SAMPLE BREAKTHROUGH Causes

    High concentrations of target compound High concentrations of similar compounds High humidity High temperatures

False Breakthrough

  Some chemicals may migrate from the front to the back sorbent layers upon storage. The method will specify freezer storage or the use of two separate tubes in these cases.

SOLID SORBENTS

SPECIFIED IN SAMPLING METHODS

 Trap and retain the contaminant even in the presence of other contaminants  Allow desorption of the contaminant  Have sufficient capacity to retain enough contaminant for analysis  Will not cause a chemical change the contaminant of

42 TYPES OF SORBENT MATERIAL: CARBON BASED SORBENTS

   Activated charcoal -Most widely used solid sorbent suitable for collection of non-polar organic compounds including benzene, toluene, and xylene. Anasorb ® 747 -Beaded carbon material that can collect a variety of both nonpolar and polar organic compounds. Carbotrap ® and Carbosieve ® High surface area; useful for very volatile compounds.

43 TYPES OF SORBENT MATERIAL: INORGANIC SORBENTS

 Silica gel Used to collect polar organic compounds such as alcohols, amines, and phenols. Silica gel is commonly used as a desiccant as it readily adsorbs water vapor.  Alumina -Not widely used at this time. Specified in one OSHA partially validated method for an amine.

TYPES OF SORBENT MATERIAL:

ORGANIC POLYMERS

 Poropaks ® , Chromosorbs ® , XAD resins and Tenax ® .  These sorbents are used to collect a variety of specialty compounds. Chromosorbs and XAD-2 are specified in NIOSH and OSHA methods for pesticides.  Tenax is specified in thermal desorption methods for (sub) ppb level VOC sampling.

SORBENT TUBES FOR SOLVENT EXTRACTION

 Sorbent tubes specified for workplace compliance sampling in the ppm range are designed for solvent extraction by the lab.

 The lab will break open the tube, pour the sorbent into vials, add a liquid solvent, and shake for a while so that the solvent extracts the contaminant from the solid adsorbent and into the liquid for GC analysis.

SORBENT TUBES FOR THERMAL DESORPTION

 Sorbent tubes specified for low level sampling in the ppb range are designed for thermal desorption by the lab.

 The lab will place the tube into the thermal desorber and apply heat and an inert gas to drive contaminant molecules from the adsorbent material to the detector of the GC.  Provide lower detection limits.

TYPES OF SORBENT MATERIAL:

MISC.

PUF Cartridges -used for semi-volatiles including PCBs and pesticides by ASTM or EPA methods . Not specified in any workplace methods.

TYPES OF SORBENT TUBES:

MISC.

Sorbent/Filter Combination s •Filters capture or scrub out particulate phase; sorbents capture vapor phase. •Specified in OSHA or NIOSH methods for pesticides, glycols, and hydrogen sulfide. OVS

H2S

49 TYPES OF SORBENT MATERIAL: WASHED OR COATED

 Some chemicals are not effectively trapped by any solid sorbent without special preparation.  Washing is done of silica gel to trap inorganic acids such as hydrochloric or hydrofluoric.

 Chemical coating is done on various sorbents to trap aldehydes, nitrogen dioxide, amines, and many more compounds.

SORBENT TUBE SAMPLING

ADVANTAGES 50

 Sample is integrated over the entire period of exposure.

 Published methods exist with extensive testing and documentation of reliability.

 Workplace compliance officers typically use this sampling method.  Air flow is calibrated and measured.

 Backup layer indicates sample breakthrough.

IMPINGERS

INTRODUCTION

Impingers are specially designed glass bottles that are filled with a collection liquid specified in the sampling and analytical method.

NOTES ABOUT IMPINGERS

In some cases, the impinger nozzle is

fritted

or modified with thousands of small holes. This disperses the air and allows for better contact between the air sample and the impinger liquid.

SAMPLE COLLECTION

WITH IMPINGERS 53

A sample pump is used to bubble air through the impinger which contains a liquid reagent that has been specified in the method. The liquid will physically dissolve or chemically react with the chemical of interest. Trap

CHEMICALLY TREATED FILTERS INTRODUCTION 54

 Alternative to wet chemistry methods  Filters are used as a substrate for liquid media that can trap contaminants.

 Liquid media will chemically derivatize the contaminant of interest.

 Result is a more stable compound for storage and analysis.

SAMPLE COLLECTION

WITH COATED FILTERS

TREATED FILTERS

COMMONLY USED TYPES

56 Chemical Treatment of Glass Fiber Filters

    2,4 DNPH 1-(2-pyridyl) piperazine Sulfuric Acid Mercuric Acetate

Applications

    Glutaraldehyde Diisocyanates (HDI,MDI,TDI) Aromatic Amines Mercaptans

TREATED FILTERS

ADVANTAGES

 Sample is integrated over the entire period of exposure.

 Published methods exist with extensive testing and documentation.

 Workplace compliance officers use these methods for some compounds.

 Air flow is calibrated and measured.  Front and back filter can be used in one cassette to determine breakthrough.

SAMPLE BAGS

INTRODUCTION

  Used since the 1950’s to collect a fixed volume of an air-contaminant mixture into a flexible container for subsequent analysis Called “ grab ” samples in industrial hygiene and “ whole air ” samples in environmental field.

SAMPLE COLLECTION

WITH SAMPLE BAGS 59 Positive Pressure Negative Pressure

SAMPLE BAGS

SPECIFIED IN SAMPLING METHODS 60

    Benzene in NIOSH 3700 Carbon Dioxide in OSHA ID 172 Carbon Monoxide in OSHA ID 210 Ethylene Oxide in NIOSH 3702     Nitrous Oxide by NIOSH 6000 Sulfur hexafluoride in NIOSH 6602 Trichloroethylene in NIOSH 3701 Various hydrocarbons in EPA 0040 and EPA SOPs

Also see www.skcinc.com

for SKC studies on bags.

SAMPLE BAGS

BAG MATERIAL OPTIONS

   

Tedlar ®-

Classic bag for 1-2 day storage of organic vapors.

SamplePro FlexFilm

-Tedlar alternative; Useful for storage times ≥3 days for many organic vapors.

FlexFoil -

Useful for gases such as CO, CO 2 , H 2, methane, and hydrogen sulfide

FlexFoil Plus

-Suitable for all the same gases as FlexFoil (above) PLUS organic vapors

SAMPLE BAGS

APPLICATIONS

 Leaks, spills, emergency situations requiring rapid collection and analysis  Peak concentrations from specific plant processes or worker tasks  Field applications using on site portable, direct-reading instruments like PIDs  Gases or highly volatile compounds for which sorbent tubes are not suitable

63 STAINLESS STEEL CANISTERS:

SPECIFIED IN EPA VOC METHODS

  Canisters have been used as an air collection vessel for measurement of low level VOCs. The interior of the canister is treated in some way so that it does not react with collected compounds.

STAINLESS STEEL CANISTERS:

SPECIFIED IN EPA VOC METHODS

The canister sampling train includes:

    Stainless steel sampling inlet Particle filter Critical orifice Flow controller

A vacuum gauge is used to visually monitor canister status during sampling.

Source: www.restekcorp.com

CANISTER SAMPLING: THE BASICS

   Most canister sampling is done “passively” using a canister that has been evacuated to a specified vacuum level. Prior to sample collection, a qualified laboratory should clean and certify the canister, evacuate the canister to the appropriate level, and provide sample identification.

At the sampling site, the valve is opened and air flows from the environment into the canister without the need for a pump.

SAMPLING MEDIA:

ACTIVE SAMPLING FOR PARTICULATES

DEFINING PARTICULATES

Solid and liquid matter such as: 

Dusts

particles rendered airborne during crushing or grinding of rock-like material   

Fumes

airborne solid particles formed above molten metal

Mists

droplets rendered airborne by bubbling, boiling, spraying or splashing

Smokes

particles resulting from incomplete combustion of organic matter

THE HAZARD POTENTIAL

OF AIRBORNE PARTICULATES

Determined by:  Chemical composition  Mass concentration  Size characteristics

SIZE CHARACTERISTICS

OF AIRBORNE PARTICULATES 69

Determine the deposition site in the respiratory tract. Smaller particles will tend to deposit deep into the gas exchange region of the lung.

SIZE-SELECTIVE EXPOSURE GUIDELINES

To more appropriately assess the possible health effects of airborne particulate matter, exposure guidelines have been issued for different sizes of particles.

TRADITIONAL PARTICULATE SIZE-SELECTIVE CRITERIA

 Total Dust  Respirable Dust

TOTAL DUST

DEFINED

 Dust that is captured onto a 37-mm filter loaded into a cassette and connected to a sampling pump calibrated to a flow of at least 1 L/min.  The filter should be of a type and pore size appropriate to the particulate being sampled.

 Samples are collected in an area or in the breathing zone of workers.

TOTAL DUST SAMPLING

IN THE BREATHING ZONE

TYPES OF FILTER MEDIA

MIXED CELLULOSE ESTER 74

APPLICATION  Asbestos, Fibers 25-mm with Conductive Cassette  Metals 37-mm with SAN Cassette  Oil Mist (Mineral) ANALYSIS  Cleared, Microscopic Analysis  Digested, Atomic Absorption or ICP  Infrared Spectrophotometry

TYPES OF FILTER MEDIA POLYVINYL CHLORIDE

APPLICATION  Particulates, Not Otherwise Classified  Silica  Chromic Acid and Hexavalent Chromium ANALYSIS  2-hour + weighing equilibration,  X-Ray Diffraction or Spectrophotomery  Visible Absorption Spectrophotometry or Ion Chromatography

TYPES OF FILTER MEDIA GLASS FIBER/QUARTZ

APPLICATION  Pesticides   Coal Tar Pitch Volatiles, Selected PAHs PCB’s  Mercaptans, Isocyanates and more

when coated

ANALYSIS  Gas Chromatography  High-Performance Liquid Chromatography (HPLC)

TYPES OF FILTER MEDIA PTFE

APPLICATION  Select PAHs  Ambient particulates ANALYSIS  HPLC  Gravimetric

CLOSED-FACE VS OPEN-FACE SAMPLING WITH CASSETTES 78



Closed-face sampling

refers to sample collection with the inlet piece of the filter cassette in place. 

Open-face sampling

refers to sample collection with the inlet removed. This approach is used for asbestos using 25-mm conductive cassettes.

RESPIRABLE DUST

DEFINED

 Also collected onto a filter of a type and pore size that is appropriate for the particulate being sampled (typically PVC filters).

 Preceding the filter, however, is a particle size-selective device, typically a cyclone, that will separate the respirable fraction from the non-respirable fraction when connected to a pump sampling at the designated flow rate.

CYCLONES

 Named for the rotation of air within a chamber  Function on the same principle as a centrifuge  Use rapid circulation of air to separate particles according to their aerodynamic diameter

WHY USE A CYCLONE?

 Some chemicals are regulated as respirable dust and cyclones enable collection of the

respirable

fraction.

 Collecting larger, non-respirable particulates would inflate results of sample, overestimating exposure.

CYCLONE OPERATION

 Air enters through a slit on the side of the cyclone which creates cyclonic action.

 Large particles fall into red “grit pot” and are discarded.

 Small particles are thrown onto the filter for analysis.

Red cap must be in place .

50% CUT-POINT: A PERFORMANCE SPECIFICATION 83

 The 50% cut-point is often used to describe the performance of size selective samplers.

 It is the particle size that the device can collect with 50% efficiency.  Particles smaller than the 50% cut point of the cyclone are collected with an efficiency greater than 50%.

 Larger particles are collected with an efficiency less than 50%.

84 DIFFERENT CYCLONE OPTIONS

   All cyclones are not created equal! Each cyclone has different operating specifications and performance criteria. Be sure you know the flow rate specified to achieve the desired cut point before using a cyclone.

85 CYCLONES AND AGENCY METHODS

 Currently, the only cyclone that OSHA inspectors can use is the nylon Dorr-Oliver at 1.7 L/min.  The NIOSH method for respirable dust specifies the use of three cyclone options including the SKC aluminum cyclone at 2.5 L/min.

NEW PARTICULATE SIZE-SELECTIVE CRITERIA

Adopted by many Global Occ Hygiene Agencies including ACGIH:  Inhalable Particulate Mass  Thoracic Particulate Mass  Respirable Particulate Mass

INHALABLE PARTICULATE

INTRODUCTION

   The “new total”.

Term used to describe particulate matter that is hazardous when deposited anywhere in the respiratory system.

This includes particulate matter that enters the head airways region including the nose and mouth.

Also includes materials that can produce systemic toxicity from deposition anywhere in the respiratory system.

INHALABLE SAMPLERS

  Defined as having a

50% cut-point of 100 microns.

Traditional filter cassettes do not effectively capture inhalable particulate matter.   The efficiency of filter cassettes falls to zero with particle sizes of 30 um and larger. Of additional concern are sample losses that occur from particles that adhere to the interior cassette walls.

INHALABLE SAMPLERS:

DESIGNED FOR THE NEW CRITERIA

   The first personal sampler specifically designed for inhalable particulate mass was developed by Mark and Vincent in 1986 at the Institute of Occupational Medicine in Scotland . The sampler was named the IOM sampler and SKC Ltd. in the UK was the sole licensee and exclusive manufacturer of this sampler for more than 20 years. The patent has now expired, but SKC is still the only company that can call this device the

IOM Sampler

IOM SAMPLER

A GOLD STANDARD

Exploded View SKC 225-70A

USING THE IOM SAMPLER GRAVIMETRIC ANALYSIS

 Load a 25-mm filter into the cassette using forceps and wearing gloves.

 Do not desiccate the filter/cassette .

 Equilibrate the filter/cassette assembly overnight under controlled humidity conditions then weigh them as a unit .

 Allow the assembly to stabilize a few minutes before taking a reading.

USING THE IOM SAMPLER GRAVIMETRIC ANALYSIS

 Place the IOM cassette/filter assembly into the sampler body, screw on the cover cap, and connect to the pump.

 Calibrate the flowrate to 2 L/min using the IOM calibration adapter or by placing in a calibration jar.  Following sample collection, weigh the cassette/filter assembly again.

INHALABLE SAMPLERS

BUTTON SAMPLER

 Alternative to the IOM sampler for inhalable particulates  Inlet has a screen to keep large particles from landing onto the filter by blasting, splashing, or other inadvertent actions.

SKC 225-360

SAMPLE COLLECTION

WITH BUTTON SAMPLER

 A 25-mm filter is pre-weighed and loaded onto the stainless steel screen.

 The sample is collected at

4 L/min

 The sample is weighed again after sample collection to determine exposure levels.

THORACIC PARTICULATE

INTRODUCTION

  Materials that are hazardous when deposited anywhere within the lung airways and the gas-exchange region.

Thoracic samplers have a

50% cut-point of 10 um.

97 THORACIC SAMPLERS OPTIONS

SKC 225-381 U.S. Patent No. 7,073,402   SKC offers an impaction based sampler for thoracic particulate called the Parallel Particle Impactor or PPI. The thoracic PPI is used with a

suitable

37-mm filter at a flowrate of 2.0 L/min.

PARALLEL PARTICLE IMPACTOR : HAS 4 INLETS OF DIFFERENT SIZES

Inlet Impaction Plate Exhaust with Final Filter   Each

impactor

consists of an inlet nozzle and exit orifice that are appropriately sized to achieve a designated cut point. The performance of each impactor matches

part

of the collection efficiency curve so that the

overall

performance closely matches the entire curve.

99 THORACIC SAMPLERS APPLICATIONS Thoracic TLVs

  Sulfuric Acid Cotton Dust

NIOSH Methods

 NIOSH Method 5524, for metalworking fluids specifies a 2-um PTFE filter in a 37-mm filter cassette with an optional thoracic particulate cyclone.

DEFINING RESPIRABLE

 Throughout the history of occupational air sampling, several definitions of “respirable” particulate matter have been proposed by different organizations in various countries.

10 0

 The main difference in the definitions is the 50% cut-point i.e. what size of dust is considered “respirable”.

SPECIFICATIONS FOR RESPIRABLE DUST SAMPLERS 10 1

 The British Medical Research Council (BMRC) originally specified samplers with a 50% cut-point of 5 microns .

 In the US, government agencies including OSHA/MSHA specify samplers with a 50% cut-point of 3.5 microns .

SPECIFICATIONS FOR RESPIRABLE DUST SAMPLERS 10 2

To reach world-wide consensus on the use of respirable dust samplers, a compromise spec was developed with a 50% cut-point of 4 microns .

 ACGIH and NIOSH have adopted this compromise spec.  OSHA and MSHA require a change to the federal regulation to make this change from 3.5 to 4.0 um cut-point.

RESPIRABLE DUST

 Conflict and confusion in the USA  NIOSH ≠ OSHA 50% cut-point of respirable samplers

CYCLONES LISTED IN CURRENT NIOSH METHODS



Nylon

at 1.7 L/min 

Higgins-Dewell

at 2.2 L/min

10 5 CYCLONES LISTED IN CURRENT NIOSH METHODS



Aluminum

at 2.5 L/min SKC 225-01-02  Each cyclone has different operating specifications and performance criteria.  Be sure you know the flow rate specified to achieve the desired cut-point before using a cyclone.

TIPS FOR SAMPLING:

WITH SKC Al OR GS CYCLONES

 Prepare 3-piece filter cassette.

 Place cyclone into middle ring.

 Calibrate the pump with sampler in line.

 Take sample at specified flow rate.

 Remove filter & cyclone from sample train.

 Replace inlet piece and send filter cassette to the laboratory for analysis.

TIPS FOR CALIBRATION

10 7



Calibration adapter

The Aluminum cyclone has a calibration chamber that fits over the stem of the cyclone which allows standard tubing to be attached for connection to the pump calibrator. SKC 225-01-03

TIPS FOR CALIBRATION

10 8

 Calibration Jar Calibration jars can also be used. But do not use an extremely large jar with the piston style calibrators. The dead volume in the jar can affect the rise/fall of the piston causing the readings to be erroneously low! SKC 225-111

10 9

TIPS FOR CALIBRATION

 Consider the “jarless” calibration method when using piston-style primary calibrators.

 Attach cyclone to calibrator pressure port and pump to suction port.

POST-SAMPLE CLEANING

11 0

   After sampling, clean all parts of the cyclone, with mild soapy water Don’t forget to clean the grit pot.

Dry the cyclone. (Air-dry or blow-dry)  Wipe with a dust-free tissue or wipe with an isopropyl alcohol moistened pad.

 Caution: Do not use strong solvents to clean plastic cyclones

11 1 THANK YOU FOR YOUR ATTENTION!

Email [email protected]

with any technical questions. www.skcinc.com