IS 15206: Work-Place Air -- Determination of Mass Concentration of Carbon Monoxide -- Method Using Detector Tubes for Short Term Sampling with Direct Indication

12 Pages·2002·1.3 MB·English

by  Bureau of Indian Standards

इंटरनेट मानक
Disclosure to Promote the Right To Information
Whereas the Parliament of India has set out to provide a practical regime of right to
information for citizens to secure access to information under the control of public authorities,
in order to promote transparency and accountability in the working of every public authority,
and whereas the attached publication of the Bureau of Indian Standards is of particular interest
to the public, particularly disadvantaged communities and those engaged in the pursuit of
education and knowledge, the attached public safety standard is made available to promote the
timely dissemination of this information in an accurate manner to the public.
“जान1 का अ+धकार, जी1 का अ+धकार” “प0रा1 को छोड न’ 5 तरफ”
Mazdoor Kisan Shakti Sangathan Jawaharlal Nehru
“The Right to Information, The Right to Live” “Step Out From the Old to the New”
IS 15206 (2002): Work-Place Air -- Determination of Mass
Concentration of Carbon Monoxide -- Method Using Detector
Tubes for Short Term Sampling with Direct Indication [CHD
32: Environmental Protection and Waste Management]
“!ान $ एक न’ भारत का +नम-ण”
Satyanarayan Gangaram Pitroda
““IInnvveenntt aa NNeeww IInnddiiaa UUssiinngg KKnnoowwlleeddggee””
“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता हहहहै””ै”
Bhartṛhari—Nītiśatakam
“Knowledge is such a treasure which cannot be stolen”

m
F’-
1S 15206:2002
ISO 8760:1990

Indian Standard
WORK-PLACE AIR — DETERMINATION OF MASS
CONCENTRATION OF CARBON MONOXIDE — METHOD
USING DETECTOR TUBES FOR SHORT TERM
SAMPLING WITH DIRECT INDICATION
.
Ics 13.040.30

@BIS 2002
BUREAU OF INDIAN STANDARDS
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002

Ju/y2002 Price Group 3
Environment Protection and Waste Management Sectional Committee, CHD 32
NATIONAL FOREWORD
This Indian Standard which is identical with ISO 8760:1990 ‘Work-place air — Determination of mass
concentration of carbon monoxide — Method using detector tubes for short-term sampling with direct
indication’ issued by the International Organization for Standardization (ISO) was adopted by the
Bureau of Indian Standards on the recommendations of Environment Protection and Waste
Management Sectional Committee and approval of the Chemical Division Council.
The text of ISO Standard has been approved as suitable for publication as Indian Standard without
deviations. Certain conventions are, however, not identical tothose used in Indian Standards. Attention
is particularly drawn to the following:
a) Wherever the words ‘International Standard’ appear, referring to this standard, they should be
read as ‘Indian Standard’.
b) Comma (,) has been used as a decimal marker while in Indian Standards, the current practice
is to use a point (.) as the decimal marker.
CROSS REFERENCE
In this adopted standard, ISO 6879:1983 ‘Air quality — Performance characteristics and related
concepts for air quality measuring methods’ has been referred, against which there is no Indian
Standard.
For tropical countries like India, the standard temperature and the relative humidity shall be taken as
27 * 2°C and 65 * 5 percent respectively.
For the purpose of deciding whether a particular requirement of this standard is complied with, the
final value, observed or calculated, expressing the result of a test or analysis, shall be rounded off
in accordance with IS 2 : 1560 ‘Rules for rounding off numerical values (revlseo’J’.The number of
significant places retained in the rounded off value should be the same as that of the specified value
in this standard.

/
IS 15206:2002
ISO 8760: 1990
.
Indian Standard
WORK-PLACE AIR — DETERMINATION OF MASS
CONCENTRATION OF CARBON MONOXIDE — METHOD
USING DETECTOR TUBES FOR SHORT TERM
SAMPLING WITH DIRECT INDICATION
1 Scope 3.3 opening time per stroke: The time taken for one com-
plete cycle of the detector-tube pump air chamber.
This International Standard specifies a method for the deter-
mination of the mass concentration of carbon monoxide
present in the air at work places (or work areas) in concentra- 4 Principle
tions greater than 10 mg/m3 using detector tubes.
Reaction of carbon monoxide present inthe air sample passing
Substances which, ifcontained inthe air mass under investiga- through a detector tube within a given period with reagents
tion and thus inthe air sample, are known to have an effect on coated on asolid support contained inthe tube, resulting inthe
the instrument reading, are indicated in clause 5. Information formation of a coloured reaction product which provides a
on performance characteristics is given in 9.2; in applications sharply defined stain in the tube.
requiring better precision or freedom from interferences, the
use of classical chemical or instrumental methods is recom- Determination of the mass concentration of carbon monoxide
mended (see 8519[100. by comparing the observed length of stain developed to lengths
of stain prepared using calibration gas mixtures, taking into ac-
The method is suitable for personal, breathing-zone sampling count the effect of interferents on the instrument reading and
as well as for the general area sampling. the correction factors for pressure, temperature and relative
humidity.
2 Normative reference
5 Reactions and interferents
The following standard contains provisions which, through
reference in this text, constitute provisions of this International Several colour-producing reactions by which carbon monoxide
Standard. At the time of publication, the edition indicated was can be detected are known. The following are used indetector
valid. All standards are subject to re v ision, and parties to tubes.

agreements based onthis International Stand ard are encouraged
to investigate the possibility of applying the most recent edition
5.1 Iodine pentoxide reaction
of the standard given below. Members of IEC and ISO maintain
registers of currently valid International Standards.
Tubes containing a reagent system based on iodine pentoxide
are length-of-stain detector tubes; the change of intensity of
ISO 6879: 1983, Air quality – Performance characteristics and
colour isfrom white to green-brown.
related concepts for air quality measuring methods.
5.1.1 Reaction equation
H2S207
3 Definitions
5C0 + 1205~ I* + 5C02
For the purposes of this International Standard, the following
definitions apply. 5.1.2 Interferents
Acetylene, aliphatic hydrocarbons, and halogenated hydrocar-
3.1 length-of-stain detector tube: A tube containing a bons are positive interferents. With the exception of acetylene,
reagent which reacts rapidly with carbon monoxide present in these can be removed by a pretreatment section.
the air sample, producing a sharply defined interface between
reacted and unreacted reagent system.
5.2 Potassium palladosulfite reaction
3.2 voluma per stroke: The amount of air or other gas mix- Tubes containing a reagent system based on potassium
ture drawn by the detector-tube pump during the opening time palladosulfite are length-of-stain detector tubes; the change of
per stroke. intensity of colour is from yellow to brown.
1
/
IS I!j206 :2002
ISO 8760: ~990
5.2.1 Reaction equetion NOTE– The intensity-of-colour development inthedetector tube isa
function of volume flow rate aawell aaof the total volume of airor
other gas mixture passed through the detector tube at a given maaa
CO + K2Pd(S03)2 = Pd + C02 + S02 + K2S03 concentration ofcarbon monoxide. The volume flow ratedependson
theauctioneffect onthedetector-tube pump andontheresistance to
flow ofthedetector tube. Theopening timeperstrokeofthedetector-
5.2.2 Interferents
tube pumpisaffected byleaksofthedetector-tube pumpandparticles
depoaited on the filter or on the wall of the flow channel of the
Carbon disulfide, halogens, mercaptans, phosphine, and detector-tube pump.
phosgene produce similar stains. Acetylene and hydrogen
sulfide produce black stains. Sulfur dioxide repreaenta a
positive interferent, butdoes notgive astain by itself.
7 Sampling
Test the detector-tube pump (6.2) for leaks by inserting an
6 Apparatus unopened detector-tube (6.1)into the inlet port ofthe detector-
tube pump and then operating the detector-tube pump. No air
should flow in the system. If air-flow occurs, as indicated by,
A complete measurement system consists of a compatible
for example, a movement of the detector-tube pump air
detector tube and detector-tube pump. These systems are nor-
chamber, leaks may be present inthe detector-tube pump, and
mally calibrated and supplied by the same manufacturer.
the detector-tube pump shall be examined and repaired or
replaced, as necessary.
6.1 Detector tubes, containing areagent thatiscoated ona
solid support and issuitable for a colour-producing reaction by Also test for flow blockage by operating the detector-tube
which the mass concentration of carbon monoxide present in pump without adetector tube. The detector-tube pump should
the air atwork places (orwork areas) can be determined incon- operate freely. If not, examine and repair or replace the
centrations greater than 10 mg/m3, within the acceptable detector-tube pump.
ranges of temperature, pressure andrelative humidity stated by
the manufacturer. Break off both ends of the detector tube and insert the opened
detector tube, with the prescribed orientation ifapplicable, into
Use only detector tubes which the inlet port of the detector-tube pump. Note that the opened
detector tube shall be tightly linked to the detector-tube pump.
a) are uniformly packed, i.e. uniform packing tightness
with no obvious segregation; Take, by operating the detector-tube pump at the previously
determined measurement point, an amount of airthe volume of
b) contain filling layers, the surfaces of which are perpen- which is prescribed by the number of detector-tube pump
dicular to the ?ube axis; strokes to be made, in accordance with the calibration data of
the detector tube.
c) are free from leaks;
and, in addition, meet the following requirementa: At the end of the sampling period, remove the detector tube
from the detector-tube pump. Flush the detector-tube pump
d) length-of-stain detector tubes s h all bedeaigned to have with clean air to protect itfrom the corrosive action of reagents
an inaccuracy of Iess than +25 % anda length of stain of or reaction products which may be released from the detector

at least 15 mm at the applicable maximum permissible tube.
value, for example Threshold Limit Value (TLV) of the mass
concentration of carbon monoxide. NOTE – Ifa hand-operated dectector-tube pump isspecified foruse
with thedetector tube, variations intheairvolume flow ratesbetween
Store the detector tubes inaccordance with the manufactu rer’s the individual detector-tube pump strokes should be minimized by
instructions, operatingthedetector-tube pumpinauniform manner, and,attheend
of each detector-tube pump stroke, an adequate interval of time for
WARNING – Detector tubes not used within the stability equalization of pressure within the detector-tube pump should be
period of the reagent system stated by the manufacturer allowed.
shall be discarded (see 8.3).
8 Procedure
6.2 Detector-tube pump, hand-operated or batterY-
~owered.
8.1 Test of the detector-tube pump
Use only the detector-tube pump specified for use with the
detector tube, which hasavolume perstroke not differing by Evaluate at stated intervals of time, or more often ifthere isany
more than + 5 ‘h from the nominal volume per stroke, which is reason to suspect the pump performance:
free from leaks, and which, when operated, givea the volume
flow rate referred to in the calibration of the detector tube. a) the volume per stroke (3.2) of the detector-tube pump,
with a representative detector tube (6.1) in Place, usin9 a
Handle the detector-tube pump carefully and maintain it ac- soap-bubble flowmeter the capacity of which is at least
cording to the manufacturer’s instructions. Test the detector- 100 ml and which iaequipped with a scale with scale inter-
tube pump as specified in 8.1. vals of 0,5 ml. For this test, connect the suction port of the
2
IS 15206:2002
ISO 8760: 1990
8.3 Disposal of detector tubes
detector-tube pump hermetically to the exit port of the
soap-bubble flowmeter; Dispose of detector tubes with due regard to the toxic or cor-
rosive reagent or reaction products contained inthe tubes, and
b) (additionally, for hand-operated detector-tube pumps) inaccordance with the manufacturer’s disposal instruction and
the opening time per stroke (3.3) with a representative national requirements.
detector tube (6.1) attached tothedetector-tube pump, in
accordance with the manufacturer’s instructions.
9 Expression of results
Compare the measured values obtained with the corresponding
calibration data of the detector-tube pump and the detector
tube. If these data donotagree within the limits stated in 6.2 9.1 Calculation
thedetector-tube pump shall beserviced or reconditioned.
The concentration of carbon monoxide in the air sample is
NOTE – The resistance to flow of the detector tube and thus the given by the detector tube indication evaluated according to
opening time perstroke differs according tothetype ofdetector tube clause 8. This concentration shall be given as mass concentra-
used. tion ,Q(CO), expressed in milligrams per cubic metre.
NOTE – Themassconcentration ofcarbonmonoxide c(CO), express-
8.2 Determination edinmilligrams percubicmetre, isrelatedtothevolume concentration
w(CO), expressed inpartspermillion (1mlperI@ ml), by the formula
! Immediately after completion of sampling, hold the used detec-
tor tube next to an unused detector tube (6.1) against a white @(co)= 28,0 X /J X 293,2 $?(co)
x
background inadequate lighting, but not indirect sunlight, and 24,05 X ((7 + 273,2) X 101,3
proceed as specified in 8.2.1 and 8.2.2.
——63,3+7 x p x @(co)
273,2
8.2.1 Evaluation of detector tube indication
where
The evaluation of the detector tube indication should be made p isthe pressure, in kilopascals, of the air sample;
only by a person trained and experienced in detector tube @ isthe temperature, in degrees Celsius, of the air sample;
reading.
28,0 isthe molar mass, ingrams permole, ofcarbon monoxide;
Evaluate the length of stain obtained by comparison with 24,05 isthe molar volume, in Iitres per mole, of an ideal gas at
-- lengths of stain associated with known concentrations of car- 293,2 Kand 101,3 kPa.
bon monoxide, usually marked on the detector tube. Apply the At293,2 Kand 101,3 kPatheconversion factors forcarbon monoxide
following rules: are
1ppm = l,16mg/mq
a) if the leading edge of the stain is not sharply defined,
take the reading at the point where slight discoloration can 1mg/ms = 0,86 ppm
just be distinguished from the colour of the unreacted

reagent system;
9.2 Precision

b) if the leading edge of the stain is not perpendicular to
the detector tube axis, take the mean resulting from the Relative errors indetector tube measurements are greater at the
shortest and the longest length of stain, provided that the lower end of the measuring range than at the higher end. The
difference between the shortest and longest length of stain maximum permissible random error, expressed as twice the
isnot greater than 20 YO of the mean. Discard the detector relative standard deviation (coefficient of variation) of detector
tube reading incases where this requirement isnot fulfilled. tube measurements specified in this International Standard is
+ 25 % at the mass concentration Ievei of carbon monoxide of
Record the concentration of carbon monoxide associated with 60 mg/m3. Some of the major sources of variation in detector
the length of stain obtained. tube measurements are:
I
a) variability of the internal diameter ofthe glass tubes; for
8.2.2 Evaluation of correction factors example, a tolerance of *O, 1 mm isa * 4 70 variation in a
5 mm internal diameter detector tube;
The length of stain obtained and intensity of colour developed
may be a function of temperature, pressure and relative humi- b) variability of the filling layer containing the reagent
dity ofair sample and may also be affected by substances other system for the colour-producing reaction; important
than carbon monoxide present in the air sample. parameters are, for example, purity and uniformity of
distribution ofthe reagent system, uniformity of particle size
In some cases, the interfering effects shall be taken into and bulk density of the solid substrate, and alignment of the
account by applying correction factors. Therefore, evaluate, if filling layer in the detector tube;
necessary, correction factors appropriate for interpreting the
detector tube reading, referring to, for example, correction c) variability of the air volume and air volume flow rate due
factors supplied by the manufacturer of the detector tube. to the flow characteristics of the detector-tube pump.

3
IS 15206:2002
ISO 8760: 1990
10 Test report g) temperature, pressure and relative humidity of the air
sample;
The test report shall include at least the following information:
h) interferents known or suspected to be present inthe air
a) identification data for the air sample;
sample;
b) reference to this International Standard;
i) mass concentration of carbon monoxide, expressed in
c) location inwhich the air sample was taken and whether
milligrams per cubic metre, as determined by the measure-
personal or general area; ment with the detector tube;
d) identification of the manufacturer of the detector tube
and detector-tube pump used, the manufacturer’s detector j) name of the person who performed the measurement.
tube batch number, and the detector tube expiry date;
e) start time and end time of the sampling period; The test report shall also contain, ifavailable, the mass concen-
tration of carbon monoxide, expressed in milligrams per cubic
f) number of detector-tube pump strokes or volume of metre, as determined by a method other than measurements
the air sample; with detector tubes.

I

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[S 15206:2002
1S0 8760:1990
Annex A
(normative)
Calibration of detector tubes
Detector tubes suitable for the determination of the concentra- for generating the calibration gas mixture by a butt-to-butt
tion of carbon monoxide present in the air at work places (or glass joint with, for example, a polpinyl chloride connection.
work areas) as commercially available and specified in6.1 have Insert the free end of the detector tube into the inlet port of the
been calibrated by the manufacturer of the detector tubes detector-tube pump. Note that the detector tube shall be tight-
using calibration gas mixtures. These shall be mixtures of car- lylinked to the detector-tube pump and proceed as specified in
bon monoxide and a complimentary gas (e.g. purified air or clause 7.
nitrogen). The composition of these mixtures shall be known
within specified limits. At the request of the user, the manufac- Immediately after completion of sampling, hold the detector
turer of the detector tubes shall supply the calibration data for tube next to an unused detector tube (6.1) against a white
the detector tubes. Therefore, recalibration of detector tubes is background inadequate lighting, but not indirect sunlight, and
required only in exceptional cases. proceed as specified in 8.2.1.
Recalibration of detector tubes can be carried out by the user of For length-of-stain detector tubes, prepare a calibration graph
the detector tubes provided that staff trained and experienced by plotting the length of stain observed in the tube versus the
in preparing calibration gas mixtures are available. Some mass concentration v(CO), expressed in milligrams per cubic
remarks on carrying out the calibration of detector tubes metre, or volume concentration Q(CO), expressed in parts per
specified in 6.1 are given below. million, of carbon monoxide present in the calibration gas
mixtures.
Prepare calibration gas mixtures following one of the static or
dynamic methods listed inannex Bor, preferably, by the use of Record the volume of gas mixture passed through the detector
standardized compressed gas cylinders containing, for exam- tube, as well as the sampling period.
ple, 0,1 % (V/VI carbon monoxide (CO) in nitrogen (Nz) in a
dynamic gas flow mixing system. Prepare a zero gas and Evaluate the range of values of temperature and the range of
several gas mixtures at different concentration levels of carbon values of relative humidity for which the calibration graph (see
monoxide within the accuracy of + 5 ‘h covering the working ISO 6879) isvalid and, in addition, evaluate calibration graphs
range, for example 10 mg/m3, 20 mg/ma, 40 mg/m3, for further values of temperature and relative humidity. Proceed
60mg/ma, lCOmg/m3and 200mg/m3. as specified above.
NOTE – The concentration of csrbon mono x ide inthe gas mixture NOTE – Thecalibration graphsshouldbevalidforgasmixtures having
tgreoncehreamteidcalshmoeutlhdobdei(nsdeeepIeSnOde8n5tl1y9[lovl)e,rified by, fo r example, anelec- aaptpermoxpiemraattuerlye 5o0fb70e.tween 18‘C and 30 “Canda relative humidity of
Evaluate the repeatability within the laboratory of the detector
At each of theselected concentration levels, take at least five
tube measurements at, for example, mass concentrations of
samples as follows:
carbon monoxide of 10 mg/m3, 20 mg/ma, 40 mg/ma,
60 mg/m3, 100 mg/m3 and 200 mg/m3, using the results of at
Test the detector-tube pump (6.2) for leaks by inserting an
least five detector tube determinations at each of the selected
unopened detector tube (6.1)into the inlet port of the detector-
concentration levels.
tube pump and then operating the detector-tube pump. No air
should flow in the system. If air-flow occurs, as indicated by,
Determine substances which are potential interferents in the
for example, a movement of the detector-tube pump air
use of detector tubes (see 5.1.2 and 5.2.2). Evaluate their ef-
chamber, leaks may be present inthe detector-tube pump, and
fects on the detector tube reading as specified above and
the detector-tube pump shall be examined and repaired or
record them.
replaced, as necessary. Also test for flow blockage by
operating the detector-tube pump without adetector tube. The
NOTE – Incaseswhere the effects of interferents can be reduced or
detector-tube pump should operate freely. If not, examine and eliminated by connecting a pretreatment tube containing a suitable
repair or replace the detector-tube pump. Break off both ends reagent coated onasolidsupport inserieswith thedetector tube, cor-
of the detector tube and connect the opened detector tube, responding calibration graphs for the detector tube and the pretreat-
with the prescribed orientation ifapplicable, to the device used ment tube shallbeprepared.

5