TM 5-815-1/AFR 19-6
(1) Total suspended particulates. The high
in economically unacceptable manpower
volume air sample is the federal reference
requirements. In these cases, sampling with
method for measuring total suspended
continuous instruments and recording on
particulates. Air is drawn (at 40 to 60
data charts provides a lower cost solution.
ft3/min) through a glass fiber filter by means
(2) Air quality regulations require the measure-
of a blower, and suspended particles having
ment of extremely small pollutant con-
an aerodynamic diameter between 100 and
centrations (1/100 of a part per million by
1.0 micron are collected. The suspended
volume). Sensitive instruments capable of
particulate is calculated by dividing the net
detecting small concentrations are needed.
weight of the particulate by the total air
c. Sampling method for carbon monoxide. The fed-
volume samples and is reported in ug/m3.
eral reference method for measuring carbon monoxide
(2) Coefficient of haze (C OH). A few states
is the instrumental nondispersive infrared technique. A
have standards for a particulate measurement
typical instrument consists of a reference cell filled
called the coefficient of haze. This measure-
with CO free air, and a sample, or detector, cell. The
ment is reported in units of COH/1000 linear
feet of sampled air. In this method, air is
through the sample cell and the reference cell is sensed
drawn through a small spot on a circle of
by a photon detector. The difference is a measure of
filter paper until the equivalent of a 1000 feet
the optical absorption of the CO in the sample cell and
long column of air of the diameter of the spot
is proportional to the CO concentration in the sample.
has passed through the filter paper.
The signal from the detector is amplified and used to
Transmittance through this spot then serves
drive an output meter as a direct measure of CO
as a measurement of particulate material
concentration. This method is precise and accurate.
collected on the filter. There are considerable
d. Sampling method for sulfur dioxide. The West-
doubts as to the usefulness and true meaning
Gaeke sulfuric acid method is the Federal reference
of COH data, since the transmittance
method for measuring sulfur oxides. The West-Gaeke
recorded is a function of the nature of the
method is a discrete bubbler technique which involves
particulate as well as the total weight
bubbling ambient air through an impinger for 24 hours.
sampled.
Sulfuric acid is added to the absorber to eliminate
(3) Dustfall (settleable particulates). Several
states have standards for the amount of par-
in a tetrachloromercurate solution. When acid bleach
ticulate that settles out of the air over a given
pararosaniline is added to the collected SO2 together
length of time (one common unit is grams/
square meter/30 days). The method of
with formaldehyde, a red-violet compound is formed
collection is generally the dust bucket. A dust
which is then measured spectrophotometrically. This
bucket is a 15-inch deep metal or plate con-
method is a discrete instrumental sampling method, but
tainer with a 6-inch opening that is exposed
may be modified for continuous use.
to the air generally for a period of one month.
e. Sampling method for oxidants and ozone. The
Dust buckets should be partially filled with
instrumental-chemiluminescence method is the federal
distilled water (or antifreeze) which prevents
reference method for measuring ozone. Upon mixing
the transporting of dust out of the buckets by
ambient air and ethylene in the testing instrument,
strong winds. This water also acts as a wash
ozone reacts with the ethylene to emit light. This light
at analysis time. After evaporating the water,
is measured by a photomutiplier. If the air and ethylene
the remaining material is weighed and the
flow rates are constant, and the proportion of air and
residues are converted to the required units.
ethylene therefore known, the resulting signal can be
i. Traceable compounds. Test methods for com-
related to ozone concentration. Analyzers are cali-
pounds other than those for which standards exist are
brated with a known ozone concentration.
often useful in evaluating stack dispersion. If unusual
fuel additives are used, or if incinerators are used to
eral reference method for NO2 is the indirect measure-
dispose of specialized materials, laboratory chemists
ment of the concentration of nitrogen dioxide by
can often devise sampling methods to measure these
photometrically measuring the light intensity of wave-
compounds in the atmosphere.
lengths greater than 600 nanometers resulting from the
j. Ringelmann standards. Particulate matter such as
gas phase chemiluminescent reaction of nitric oxide
soot, fly ash, and droplets of unburned combustibles
(NO) with ozone (O3).
present in exhaust gases tend to impart blackness or
g. Sampling method for total hydrocarbons. Gas
opacity to a plume. It is assumed that the darker the
chromatography flame ionization is the federal refer-
shade of gray or black, the greater the concentration of
ence method of measuring total hydrocarbons.
particulate matter present in a plume. The Ringelmann
h. Sampling method for particulates.
5-2
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