ISO 9835:1993

SLOVENSKI STANDARD
01-oktober-1996
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Ambient air - Determination of a black smoke index
Air ambiant - Détermination d'un indice de fumée noire
Ta slovenski standard je istoveten z: ISO 9835:1993
ICS:
13.040.20 Kakovost okoljskega zraka Ambient atmospheres
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD
First edition
1993-03-15
Ambient air - Determination of a black
smoke index
- Determination d ’un indice de fum&e noire
Air ambian t
Reference number
ISO 9835: 1993(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide
federation of national Standards bodies (ISO member bodies). The work
of preparing International Standards is normally carried out through ISO
technical committees. Esch member body interested in a subject for
which a technical committee has been established has the right to be
represented on that committee. International organizations, governmental
and non-governmental, in liaison with ISO, also take part in the work. ISO
collaborates closely with the International Electrotechnical Commission
(1 EC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard ISO 9835 was prepared by Technical Committee
ISO/TC 146, Air quality, Sub-Committee SC 3, Ambient atmospheres.
Annex A of this International Standard is for information only.
0 ISO 1993
All rights reserved. No patt of this publication may be reproduced or utilized in any form or
by any means, electronie or mechanical, including photocopying and microfilm, without per-
mission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-l 211 Geneve 20 l Switzerland
Printed in Switzerland
INTERNATIONAL STANDARD
Ambient air - Determination of a black smoke index
where
1 Scope
R is the intensity of reflected light from the
This International Standard specifies a method for
surface of a stained paper-;
measuring the black smoke index of an ambient air
Sample. The method is based on the staining effect
is the intensity of reflected light from the
RO
of particles which is produced when a Sample of air
surface of a clean Paper;
is drawn through a filter Paper.
A is the area of the stain on the filter Paper,
The method is intended for the measurement of a
in Square metres;
black smoke index in the range 6 to 375 in the ambi-
V is the volume sampled, in cubic metres;
ent atmosphere. lt is based on the measurement of
reflectance. The method does not measure the mass
a is the absorption coefficient, in reciprocal
concentration of particles directly.
metres.
Thus, rearranging equation (1):
2 Definition
A RO
ZE----
a xln - . . .
(2)
R
2v
For the purposes of this International Standard, the
( 1
following definition applies.
The method specified in this International Standard
2.1 black smoke: Strongly lig ht-absorbing, tan be used to measure the absorption coefficient on
any filter material, but the conversion of absorption
particulate material suspended in the ambient atmos-
phere. coefficient or extinction coefficient to what is, by
convention, known as the black smoke index, is
The major contributor to black smoke is soot
NOTE 1 purely an arbitrary Operation which is carried out by
particles; i.e. particles containing carbon in its elemental
reference to tables or graphs. For further expla-
form.
nations, see annex A.
3 Principle and theory
4 Apparatus
Air is drawn through a filter Paper and the reflectance
of the stain produced is measured. If it is assumed
that reflected light from the surface of the filter Paper
has passed through the layer c ,f ’ light absorbent par-
4.1 Sampling equipment. The Sampler shall be
ticles twice, ref lectance f rom the filter surface is
designed for daily Operation, or it shall be of an auto-
analogous to the absorption of ight by particles sus-
matic type for continuous Operation. Flow diagrams
pended in air in accordance witt the equation
of alternative arrangements of sampling equipment
are shown in figure 1. Details of the sampling equip-
R = R, exp . . .
(1)
ment are given in 4.1.1 to 4.1.6.

4.1.1 Air intake, a conical funnel of 30 mm to b) reading the volume directly from a dry gasmeter
50 mm diameter that is constructed of having an accuracy of at least 5 % of the meas-
polyvinylchloride. The funnel shall be mounted verti- ured volume (the sampling flow rate shall be
cally with the mouth downwards at a height of not 2 m3/d & 0,2 m3/d).
less than 2,5 m and not greater than 5 m above the
ground. The inlet shall be located at least 1 m hori-
4.2 Reflectometer, consisting of a light Source and
zontally from any external Walls.
detector and having either an analogue or digital
readout of either the percentage reflectance (linear
4.1.2 Connection tubing, constructed of polyvinyl-
scale; 0 to 100 % reflectance) or the extinction coef-
chloride, of internal diameter 8 mm + 1 mm and no%
ficient (logarithmic scale; 0 to infinity) type.
greater than 6 m in length. Bends shall be avoided if
possible but, if unavoidable, shall have a radius greater
The Points on the density chartlj shall be within the
than 50 mm.
limits shown in figure 2.
4.1.3 Filter unit. The filter holder shall be con- Instruments designed according to the requirements
structed of an electrically conducting and chemically
mentioned in this subclause shall be capable of
inert material (with respect to the atmosphere likely measuring the absorption coefficient with a precision
to be encountered). The area of the aperture shall be of better than 5 % at absorption coefficients greater
5 cm* + 5 %. The leakage across the filter and valves than 1 x 10D5m- ‘.
(if used) shall not exceed 2 % of the total flow rate.
The filter holder should be of a design which will pro-
vide a homogeneous particle layer on the surface of
5 Procedure
the filter medium.
The homogeneity of the particle layer tan be checked
5.1 Sampling
by measuring the reflectance at several Points across
the diameter of the stain produced by sampling par-
Assemble the sampling train in the Order illustrated in
ticles using the filter holder. The Variation in
figure 1 using the specified connection tubing (4.1.2)
reflectance across the stain shall not exceed 1 per-
for all connections. Place a clean sheet of filter Paper
centage unit of reflectance.
(4.1.4) in the filter unit. If the two faces of the Paper
do not have the same texture, place the Paper so that
4.1.4 Filter material. The filter membrane shall
the suspended particulate matter is collected on the
have a collection efficiency of as close to 100 % as
smoother surface.
possible in the 0,l micron to 5 micron particle size
Assemble the filter unit (4.1.3) according to the
range. Variations in reflectance across the whole sur-
face area shall not exceed 1 reflectance unit. In ad- manufacturer ’s instructions. Check the assembled
equipment for leakage.
dition, the filter material shall be suitable for a flow
rate of 2 m3/d.
Record the initial reading of the gasmeter (if fitted).
NOTE 2 The reflectance of unused filters may vary from
Start the sampling pump (4.1.5), adjust the sampling
batch to batch, and it is therefore necessary to check and
rate to 1,4 I/min (2 m ’/d) and note the starting time.
adjust for the variability of the filters before use.
Sample for 24 h.
4.1.5 Sampling pump, capable of delivering up to
At the end of the sampling period, record the flow
2,0 I/min of air with the filter in line. If a membrane
rate and time, switch off the sampling pump and re-
pump is used, a 0,2 litre ballast shall be incorporated
cord the final reading of the dry gasmeter (if fitted)
to minimize pressure fluctuations. The pump is placed
and the sampling period to the nearest hour and min-
before the flow or volume meter (see figure 1).
ute.
4.1.6 Volume measurement and flow rate
Calculate the volume sampled, in cubic metres, using
control, consisting of a Sampler equipped with a flow
the flow rate and the Sample duration or using the
controller capable of keeping the flow rate constant
readings of the dry gasmeter. (See also 4.1.6.)
to within + 5 % of the measured flow. Measure the
volume sahpled by either
5.2 Calibration of the reflectometer
a) recording the elapsed time and calculating the
Calibrate the reflectometer according to the manu-
volume sampled under the control of the flow
facturers’ instructions.
controller; or
1) Kodak Publication No. Q-16.
a) Alternative 1
4 5
2 3
b) Alternative 2
KeY
1 Air intake
2 Filter clamp
3 Sampling pump
4 Dry gasmeter
5 Flow controller
Variable area flowmeter
7 Elapsed time meter
Alternative sampling arrangements for black smoke measurement
Figure 1 -
Ref lection density
.O,S
x
c
.-
t
0 0,4
.-
c
U
aJ
r”
it!
-Ei
5 083
d
it!
O,l
02 0,3 084 05 0,6 67
Actual ref lection density (f rom ref lection density Chart)
Reflectometer response
Figure 2 -
5.3 Measurement of the reflectance of
6 Expression of res
...