Air Pollution
Sampling
&
Measurement
Instruction Manual
L
M
o
tt
TABLE OF CONTENTS
How to Establish a Meaningful Air Monitoring Program ..................... 3
Equipment Requirements ........................................................... 3
Establishing a Sampling Site ...................................................... 5
Air Sampling Apparatus:
Air Sampling Pump ....................................................................... 7
Instructions ............................................................................... 7
AC Operation........................................................................... 9
Battery Replacement .................................................................. 9
Maintenance of Flowmeter ......................................................... 9
Storage.................................................................................... 9
Hand Operated Syringe Pump ..................................................... 10
Instructions ............................................................................. 10
Conversions ............................................................................... 11
Flow Equivalents ......................................................................... 11
Combination Air Pollution Test Kits ................................................ 12
Individual Air Pollution Test Kits ..................................................... 13
General Precautions ................................................................... 14
Packaging & Delivery ................................................................... 15
Limits of Liability ......................................................................... 15
2 Air Pollution Sampling & Measurement
HOW TO ESTABLISH A MEANINGFUL
AIR MONITORING PROGRAM
To set up a program for monitoring air pollution there are two basic
requirements. First, a means of collecting and analyzing the air sample is
required. Second, a strategic plan for continuous sampling at a series of
logical monitoring sites must be established. The recording of data over
a period of time is important in observing the variations that take place
at the monitoring sites.
EQUIPMENT REQUIREMENTS
Most of the sampling in air pollution studies is done with some type of
vacuum equipment. The vacuum is required to draw an air sample
through a chamber holding a special absorbing solution. The absorbing
solution is chemically selective for a particular gas, and is held in a
special glass bubbling tube called an impinger. Since gaseous pollutants
differ chemically, the absorbing solutions are also different.
In order to make a quantitative test, a means to measure the amount of
air that is drawn through the absorbing solution has to be known. This is
done by the use of an adjustable flowmeter. A flowmeter is simply a
device to measure the rate of flow of the air through the absorbing
solution. For most air pollution studies the flowmeter is calibrated to
measure the rate of flow in liters per minute (Lpm).
When a flowmeter is attached to the vacuum portion of the air sampling
train, one can accurately monitor the amount of air which is pulled
through the absorbing solution. A flowmeter with an adjustable flow
device - like a needle valve - can be used to preset the vacuum pump to
sample at a known rate. If one draws air through the absorbing solution
at 2.0 Lpm for 10 minutes, then 20 liters of air have been sampled.
As one of the most important components of the air sampling train, the
vacuum pump must meet certain requirements. If one is interested in
taking air samples from outdoors, the vacuum equipment must be
battery operated and completely portable. It should also possess a
means for regulating the amount of air sampled. Vacuum equipment
meeting these criteria would be useful for most applications. Air pumps
that push the air through the pump first and then through the impinging
equipment should be avoided. Proper sampling techniques require that
the air sample be “sucked” through the impinger prior to its contact with
the pump. The pump should have the ability to maintain a particular
flow rate for a pre-determined time. Air sampling equipment should be
completely portable, possess a regulating device for sampling at
different rates, and be able to maintain a particular sampling rate for a
known amount of time.
Air Pollution Sampling & Measurement 3
Impinger devices are available in various shapes and sizes. The simplest
impinger device consists of a glass vial plus a stopper with a short glass
tube and a longer glass tube. The long tube is immersed into the
absorbing solution. Other types of impingers are more sophisticated and
may meet the specifications set forth by the American Public Health
Association or some other regulatory agency.
In principle, the inexpensive impingers and the precision impingers
operate in a similar fashion. Some precision impingers have a fitted
glass end which is immersed into the absorbing solution. This enables
the impinger to disperse many minute bubbles. The smaller the bubbles,
the more surface contact is permitted between the gas and absorbing
solution and a higher efficiency of gas absorption results. A fritted glass
bubbler of this description is used for nitrogen dioxide determinations.
For other determinations, a plain glass bubbler assembly is used which
usually has a 1 mm opening at the end for dispersing the air sample into
the absorbing solution.
The individual chemical test modules used to analyze the absorbing
solution after impingement are based upon established methods for
testing air pollutants. For convenience and portability these testing units
are furnished in compact carrying cases. All of the necessary apparatus
and reagents needed to conduct a chemical analysis of the air are
included within the testing outfit.
The reagent systems included in the testing units include an absorbing
solution which extracts the chemicals from the atmosphere. In some
systems a single indicator is added to the absorbing solution to cause a
color reaction. In other systems, the absorbing solution is pre-treated
before the indicator is added. The color reaction is measured in a visual
comparator or an electronic colorimeter.
Visual comparators are devices for matching the color of the test sample
to color standards of known value. Each comparator contains eight
permanent color standards. The color standards have an index,
numbered one through eight. The number refers to a calibration chart in
the instructions for each test. After the recommended testing procedure
is completed for a particular test, note which index gave the proper color
match and refer to the calibration chart.
Regardless of whether the air pollution test equipment is used for testing
air pollution levels in confined areas or for monitoring atmospheric
pollutants in the field, significant results are obtained only if correct
analytical techniques are used. Clean glassware and uncontaminated
reagents are important for accurate results. Sampling apparatus should
be checked periodically to insure proper operation.
4 Air Pollution Sampling & Measurement
Some of the reagents require special handling as they are capable of
causing skin irritations. No chemical reagent should be taken internally,
but if accidentally ingested, heed the antidote label on the bottle and
contact a physician immediately. Reagents which are marked poison
should be treated as such. Careful handling of all chemicals is a
necessary part of chemical testing. Follow all instructions as outlined in
the individual directions for each test.
ESTABLISHING A SAMPLING SITE
To establish a meaningful air pollution monitoring program, one must
take a complete survey of the area and prepare a sampling map to
select a sampling site. Consider which sources might be responsible for
contributing to air pollution. Where are these sources? Determine
whether pollution control devices are being used and whether these
devices are operating correctly. Heavy industrial areas contribute
significantly to the total pollution in an area. Determine what tests should
be used to accurately monitor industrial emission.
When recording data on sampling, take into account meteorological
data such as the prevailing winds, temperature inversions, rainfall and
other factors which affect the dispersion of air pollutants. Try to set up a
remote sheltered location away from the normal air pollution sources or
a control for comparison purposes.
Another significant source of air pollution is the automobile. To
familiarize you with how each car contributes to air pollution, check the
emissions from a single car. Compare new cars with emission control
devices to older cars with limited or no emission control devices.
Determine what major pollutants are emitted from the exhausts of other
internal combustion engines, e.g. lawn mowers. The exhausts from
internal combustion engines are poisonous. Never work in confined
areas without adequate ventilation. Work with proper supervision.
Locate the traffic laden roads of your community during rush hour.
Compare the amount of pollution with the number of cars at different
times. Compare results of tests to data compiled during non-rush hour
traffic conditions. How may these pollutants be dispersed by
meteorological conditions?
For classroom studies and to familiarize students with the chemical
procedures it may be necessary to demonstrate the basic principles of
collecting and measuring air pollution factors. Certain gaseous
pollutants such as ammonia, chlorine, and total oxidants are easily
demonstrated because of the simple chemical procedure involved and
also because these gases are readily available as household or standard
laboratory supplies — ammonia cleaners, bleach, hydrogen peroxide,
etc.
Air Pollution Sampling & Measurement 5
Prior to any field trips, it is necessary to prepare a checklist of the
components required for conducting an air pollution study. An inventory
of the required chemical reagents should be compiled before taking the
unit into the field for testing. The battery capacity for the sampling
apparatus should be checked. A supply of reserve batteries might
prevent an interruption in the middle of a sampling period. Plan in
advance.
To record the results of air pollution investigations, one should include
such items as the following: meteorological data — prevailing winds,
temperature, atmospheric pressure, relative humidity; duration and time
of sampling; location of sampling site; sampling and test procedure;
and finally the concentration of the pollutant. Any observations which
might adversely affect the result should also be noted.
After compiling data from a particular investigation, check results from
previous surveys from your own or other schools, local health agencies,
or state and federal monitoring programs.
6 Air Pollution Sampling & Measurement
AIR SAMPLING APPARATUS
AIR
SAMPLING
PUMP
IN
OUT
2.0
1.5
1.0
.5
LPM AIR
ON • OFF
BATTERY
OPERATION
7 ml
20 ml
30 ml
40 ml
5 ml
10 ml
15 ml
25 ml
CODE 0922l
AC Adapter
Jack
Impinger
Tube
(0922)
Outlet
Tube
Stopper
Assembly
Intake
Tube
Flexible Tubing
Pump Intake
Fitting
Flowmeter
Diagram 1
AIR SAMPLING PUMP MODEL BD • CODE 1949
The Model BD Air Sampling Pump is designed especially for use with the
LaMotte Air Pollution Test Equipment. Among the many features of the
air sampling pump are an adjustable flowmeter, intake and exhaust
connections, impinger holder, on-off switch, four “C” cell batteries and
AC jack. For proper maintenance and to guarantee the life and
usefulness of the air sampling pump, the following operating procedures
are recommended.
INSTRUCTIONS
1. Check battery capacity by turning switch to the “ON” position. If the
red LED on the front of the meter fails to come on, the batteries are
too weak to operate the pump. Adjust flowrate to sample at 2.0
Lpm. If indicator float of flowmeter vibrates up and down with a
deflection of more than 0.2 Lpm, or if air sampling pump cannot be
adjusted to sample at 2.0 Lpm, replace batteries (see Battery
Replacement). Alternatively the pump may be operated with an AC
adapter (1744).
Air Pollution Sampling & Measurement 7
2. Fill the impinging tube to the designated line with the absorbing
S
24
40
S
24
40
30ML
25
20
15
10
5
Outlet Tube
Intake Tube
Gas Bubbler
Impinger (0934)
Diagram 2
solution. Insert stopper assembly, thereby immersing the long tube
into the absorbing solution. Attach one end of the flexible tubing to
the pump intake fitting. The other end of the tubing is attached to
the short outlet tube of the General Purpose Impinger (0922)
(Diagram 1). The outlet connection draws air from above the liquid
in the impinger chamber. DO NOT connect to the inlet tube of the
impinger which is below the surface of liquid. Check to insure all
connections are tight and that the tubing is correctly connected to
the impinging tube before operating the pump.
NOTE: Several air sampling kits use
the Gas Bubbler Impinger (0934)
instead of the General Purpose
Impinger (Diagram 2). In Step 2, the
flexible tubing from the pump is
attached to the side outlet of the
impinger. This is a tight connection
which requires some care and patience
to make. The outlet connection draws
air from above the liquid in the
impinger chamber.
3.
Turn switch to “ON” position.
4. Adjust flowmeter to sample at the designated rate (according to
instructions of testing unit). Turn knob clockwise to reduce flow,
counterclockwise to increase flow. Do not unscrew or withdraw valve
stem beyond threaded section except for maintenance. The
flowmeter is read by aligning the reader’s eye with the center of the
black indicator float and the scale. Graduations on the scale are in
0.1 Lpm increments.
8 Air Pollution Sampling & Measurement
NOTE: To avoid introducing residue or foam into the pump a trap
may be constructed by adding an empty impinger to the flexible
tubing between the impinging tube with the absorbing solution and
the pump intake fitting. Attach the flexible tubing leading from the
impinging tube outlet to the intake of the empty impinger. Use an
additional length of tubing to attach the outlet tube of the empty
impinger to the pump intake fitting.
5. At the end of the sampling period, turn switch to the “OFF” position.
Disconnect impinging apparatus and remove from holder.
6. The absorbing solution is then subjected to the testing procedure as
outlined in the individual air pollution test instructions.
AC OPERATION
The Model BD Pump may be operated with an AC adapter (Code 1744)
by plugging jack into designated receptacle.
BATTERY REPLACEMENT
Turn switch to the “OFF” position and remove panel. The battery holder
and batteries are located under the panel. Remove old batteries and
snap new batteries into battery holder making sure batteries are aligned
properly to their positive and negative terminals as indicated.
Misalignment of the batteries may result in permanent damage to the
pump. After batteries have been replaced, return panel and secure by
tightening the four corner screws.
MAINTENANCE OF FLOWMETER
The only maintenance normally required is occasional cleaning of the
flowmeter to assure reliable operation and good float visibility. Please
contact LaMotte Company’s Technical Service Department
(800-344-3100 or www.lamotte.com) for instructions and assistance
with disassembly and cleaning of the flowmeter.
STORAGE
To reduce the effect of possible variation introduced by the interval of
collection and analysis, the time period should be kept as short as
possible, and preferably of the same duration. The sample should be
kept from exposure to heat and light. If the analysis cannot be made
immediately after the sample collection, the sample may be stored at a
low temperature.
Air Pollution Sampling & Measurement 9
HAND OPERATED SYRINGE PUMP
MODEL LG • CODE 1947
This manually operated syringe
pump is capable of drawing 50
cc of the test atmosphere through
the impinging apparatus by one
complete stroke of the syringe.
The pumping mechanism relies
upon the use of a special check
valve which assures that a positive
vacuum is formed on the upstroke
of the syringe. The check valve
also allows the expulsion of the
air sample as the plunger is
depressed.
Through the use of this mechanism a continuous sampling of the test
atmosphere is obtained as the plunger of the syringe is manually pulled
out and depressed.
A general purpose impinging apparatus is held in place by a special
holder on the barrel of the syringe. The short plastic tube of the
impinging apparatus is connected by flexible tubing to the intake
connection of the syringe. As the syringe plunger is pulled out, air is
drawn through the longer tube and bubbled into the absorbing solution.
The vacuum formed on the upstroke of the plunger draws air from
above the absorbing solution into the syringe chamber. When the
syringe plunger is depressed, the air is forced through the outlet or
exhaust of the check valve. After the syringe is in the downstroke position
it is ready for another 50 cc air sample.
INSTRUCTIONS
1. Depress plunger to “0" position.
2. Remove stopper assembly from impinging tube and pour the
designated amount of absorbing solution into the glass tube (refer
to individual test kit instructions to determine what amount of
absorbing solution is added to impinging apparatus).
3. Replace stopper assembly. Connect flexible tubing to short tube
(outlet) of impinger assembly and to intake connections of syringe.
4. Begin to sampling the test atmosphere by completing one complete
cycle (pulling out - depressing plunger). Twenty complete strokes on
the syringe per minute is equivalent to sampling the air at one liter
per minute (Lpm). Continue sampling until required volume of air
has been sampled (refer to individual test kit instructions).
10 Air Pollution Sampling & Measurement
5. At the end of the sampling period, disconnect impinging apparatus
and remove from holder. Test the absorbing solution as outlined in
the procedures in the individual test kit instructions.
devices are being used and whether these devices are operating
correctly. Heavy industrial areas contribute significantly to the total air
pollution in an area.
CONVERSIONS
The individual air pollution test sets are calibrated with readouts in parts
per million (ppm). To convert concentrations of gases and vapors from
ppm by volume to mg/M3 and vice versa at any given temperature and
pressure, the following expression is useful:
C2 (ppm) =
C1 x 24.450 x T x 760
mol. wt. x 298 x P
C1 (mg/M3) =
C1 = Concentration of gas or vapor in mg/M
C2 x mol.wt. x 298 x P
24.450 x T x 760
3
C2 = Concentration of gas or vapor in ppm
T = Absolute temperature in °Kelvin (°C + 273)
P = Absolute pressure in Torr of samples air stream (mm of mercury)
NOTE: It is usually necessary to convert the measured air flow to the
temperature and pressure of air stream.
FLOW EQUIVALENTS
1 Cu Ft/Hr = 1 Lpm =
0.016 Cu Ft/Min 60 Lph
0.471 Lpm 0.035 Cu Ft/Min
28.317 Lph 2.118 Cu Ft/Hr
471.95 cc/Min 1000 cc/Min
28317 cc/Hr 60,000 cc/Hr
0.124 Gal/Min 0.264 Gal/Min
7.481 Gal/Hr 15.852 Gal/Hr
Air Pollution Sampling & Measurement 11
COMBINATION AIR POLLUTION TEST KITS
All of the testing methods used in each outfit follow the accepted
procedures of the Environmental Protection Agency, which recommends
collection of the gas in a special absorbing solution and the subsequent
chemical analysis. Through the use of these methods, better quantitative
results may be obtained than results acquired by gas indicator tubes or
length of stain methods.
Each analytical method has been appropriately modified to make the
entire outfit suitable for testing either field conditions or conditions in
confined areas. Both precision impinging units and general purpose
impinging units are furnished in the outfit.
AIR POLLUTION OUTFIT
MODEL AM-61 • CODE 5959-01
Tests for Ammonia, Chlorine, Lead, Nitrogen Dioxide, Sulfur Dioxide,
and Total Oxidants.
COMBINATION AIR POLLUTION OUTFIT
MODEL AM-62 • CODE 5960
Tests for Ammonia, Carbon Monoxide,
Chlorine, Hydrogen Sulfide, Nitrogen
Dioxide, and Sulfur Dioxide.
12 Air Pollution Sampling & Measurement
INDIVIDUAL AIR POLLUTION TEST KITS
Each test set uses a standardized method of analysis and has been
adapted for field use. Included are the standardized test reagents, the
comparator equipment with permanent color standards, comparator
tubes, instructions and case. Inexpensive reagent refill packages are
available. Accessory equipment such as impingers and flowmeters are
available separately.
Sampling pumps are not included in these kits.
DESCRIPTION CODE
Ammonia in Air Kit 7735
Carbon Monoxide in Air Kit 7782
Chlorine in Air Kit 7973
Formaldehyde in Air Kit 6695
Hydrogen Sulfide in Air Kit 7671
Lead in Air Kit
Nitrogen Dioxide in Air Kit 7690
Sulfur Dioxide in Air Kit 7714
Total Oxidants in Air Kit 7738
*WARNING: Reagents marked with an * are considered to be potential
health hazards. To view or print a Material Safety Data Sheet (MSDS) for
these reagents go to www.lamotte.com. To obtain a printed copy,
contact LaMotte by e-mail, phone or fax.
†
7440
†Reagents in the Lead in Air Kit (7440) are banned for household use.
Air Pollution Sampling & Measurement 13
GENERAL PRECAUTIONS
A. Store in a cool, dry place to prolong reagent shelf life.
B. Read all instructions to familiarize yourself with the test procedure
before you begin. Note any precautions in the instructions.
C. Read the label on each LaMotte reagent container prior to use.
Some containers include precautionary notices and first aid
information.
D. Keep all equipment and reagent chemicals out of the reach of
young children.
E. Safety and first aid information for all LaMotte reagents is available
in the United States, Canada, Puerto Rico, and the US Virgin Islands
from Chem-Tel by calling 1-800-255-3924. For other areas, call
813-248-0585 collect to contact Chem-Tel’s International access
number. Each reagent can be identified by the four digit number
listed on the upper left corner of the reagent label, in the contents
list, and in the test procedures.
F. Avoid contact between reagent chemicals and skin, eyes, nose, and
mouth.
G. Wear safety goggles or glasses when handling reagent chemicals.
H. Use the test tube caps or stoppers, not your fingers, to cover test
tubes during shaking or mixing.
I. When dispensing a reagent from a plastic squeeze bottle, hold the
bottle vertically upside-down (not at an angle) and gently squeeze it
(if a gentle squeeze does not suffice, the dispensing cap or plug
may be clogged).
J. Wipe up any reagent chemical spills, liquid or powder, as soon as
they occur. Rinse area with wet sponge, then dry.
K. Thoroughly rinse test tubes before and after each test. Dry your
hands and the outside of the tube.
L. Tightly close all reagent containers immediately after use. Do not
interchange caps from different containers.
M. Avoid prolonged exposure of equipment and reagents to direct
sunlight. Protect them from extremely high temperatures and from
freezing.
14 Air Pollution Sampling & Measurement
PACKAGING & DELIVERY
Experienced packaging personnel at LaMotte Company assure
adequate protection against normal hazards encountered in
transportation. After the product leaves the manufacturer, all
responsibility for its safe delivery is assured by the transportation
company. Damage claims must be filed immediately with the
transportation company to receive compensation for damaged goods.
LIMITS OF LIABILITY
Under no circumstances shall LaMotte Company be liable for loss of life,
property, profits or other damages incurred through the use or misuse of
their products.
Air Pollution Sampling & Measurement 15
L
M
o
tt
LaMOTTE COMPANY
Helping People Solve Analytical Challenges
PO Box 329 • Chestertown • Maryland • 21620 • USA
800-344-3100 • t 410-778-3100 • f 410-778-6394
www.lamotte.com
36022 • 10.11
SM
Loading...