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.

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“Step Out From the Old to the New”

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“The Right to Information, The Right to Live”

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“Knowledge is such a treasure which cannot be stolen”

“Invent a New India Using Knowledge”

है”ह”ह

IS 1448-29 (2004): Methods of Test for Petroleum and itsProducts, Part 29: Petroleum Products - Gum Content ofLight and Middle Distillate Fuels - Jet Evaporation Method[PCD 1: Methods of Measurement and Test for Petroleum,Petroleum Products and Lubricants]

IS1448[P:29] :2004ISO 6246:1995

( m -@km)

Indian Standard

METHODS OF TEST FOR PETROLEUM AND ITSPRODUCTS

[P: 29]

PETROLEUM PR(3DUCTS — GUM CONTENT OF LIGHT AND MIDDLE DISTILLATEFUELS — JET EVAPORATION IWETHOD

( Third Revision)

ICS 75.160.30

0 BIS 2004

BUREAU OF INDIAN STANDARDSMANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG

NEW DELHI 110002

August 2004 Price Group 5

Methods of Measurement and Test for Petroleum, Petroleum Products and Lubricants SectionalCommittee, PCD 1

NATIONAL FOREWORD

This Indian Standard [ P :29 ] ( Third Revision ) which is identical with ISO 6246:1995 ‘Petroleumproducts — Gum content of light and middle distillate fuels — Jet evaporation method’ issued by theInternational Organization for Standardization ( ISO ) was adopted by the Bureau of Indian Standardson the recommendations of the Methods of Measurement and Test for Petroleum, Petroleum Productsand Lubricants Sectional Committee and approval of the Petroleum, Coal and Related Products DivisionCouncil.

Second revision of this standard was published in 1982 which was based on ASTM D 381 : 19751P 131 : 1977. The Committee decided to revise this Indian Standard to completely align withISO 6246:1995 and publish under the dual numbering system. Consequently the title of the standardhas been modified.

The text of ISO Standard has been proposed to be approved as suitable for publication as an IndianStandard without deviations. Certain conventions are, however, not identical to those used in IndianStandards. Attention is particularity drawn to the following:

a) Wherever the words ‘International Standard’ appear referring to this standard, they should beread as ‘Indian Standard’.

b) Comma ( , ) has been used as a decimal marker while in Indian Standards, the current practiceis to use a point ( . ) as the decimal marker.

CROSS REFERENCES

In this adopted standard reference appears to certain International Standards for which Indian Standardsalso exist. The corresponding Indian Standards, which are to be substituted in their place, are listedbelow along with their degree of equivalence for the editions indicated. However, that Internationalstandard cross-referred in this adopted ISO Standard, which has subsequently been revised, position inrespect of that latest ISO Standard has been given:

International Standard

1S0 3170:1988 Petroleum liquids —Manual sampling

ISO 3171 :1988 Petroleum liquids —Automatic pipeline sampling

ISO 3696:1987 Water for laboratoryuse — Specification and test method

ISO 4788:1980 Laboratory glass-ware — Graduated measuringcylinders

ISO 6353-2 : 1983 Reagents forchemical analysis — Part 2 :Specification — First series

ISO 6353-3 : 1987 Reagents forchemical analysis — Part 3 :Specification — Second series

Corresponding Indian Standard

IS 1447 ( Part 1 ) :2000 Petroleumand its products — Methods ofsampling : Part 1 Manual sampling( first revision)

Nil

IS 1070:1992 Reagent grade water( third revision)

IS 878:1975 Graduated measuringcylinders ( first revision )

Nil

Nil

Degree of Equivalence

Technically equivalentwith minor deviations

—

Technically equivalentwith minor deviations

do

—

—

( continued on third cover)

IS 1448 [ P :29 ] :2004ISO 6246:1995

Indian Standard

METHODS OF TEST FOR PETROLEUM AND ITSPRODUCTS

[P: 29]

PETROLEUM PRODUCTS — GUM CONTENT OF LIGHT AND MIDDLE DISTILLATEFUELS — JET EVAPORATION METHOD

( Third Revision)

WARNING — The use of this International Standard may involve hazardous materials, operationsand equipment. This standard does not purport to address all of the safety problems associatedwith its use. It is the responsibility of the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatory limitations prior to use.

1 Scope

This International Standard specifies a method for thedetermination of the existent gum content of aviationfuels, and the gum content of motor gasolines orother volatile distillates in their finished form, and atthe time of test.

For non-aviation fuels, a procedure for the determi-nation of the heptane-insoluble portion of the residueis also described.

CAUTION — This method is not intended for thetesting of gasoline components, particularly thosewith a high percentage of low-boiling unsaturatedcompounds, as they may cause explosions duringevaporation.

NOTE 1 The true significance of this test method for de-termining gum in motor gasoline is not firmly established.It has been proved that high gum content can causeinduction-system deposits and sticking of intake valves, andin most instances it can be assumed that low gum contentwill ensure absence of induction-system difficulties. Theuser should, however, realize that the test is not of itselfcorrelative to induction-system deposits. The prima~ pur-pose of the test, as applied to motor gasoline, is the meas-urement of the oxidation products formed in the sampleprior to or during the comparatively mild conditions of thetest procedure. Since many motor gasolines are purposelyblended with non-volatile oils or additives, the heptane ex-traction step is necessary to remove these from the evap-oration residue so that the deleterious material, gum, maybe determined. With respect to aviation turbine fuels, largequantities of gum are indicative of contamination of fuel by

higher boiling oils or particulate matter and generally reflectpoor handling practices in distribution downstream of therefine~.

2 Normative references

The following standards contain provisions which,through reference in this text, constitute provisionsof this International Standard. At the time of publi-cation, the editions indicated were valid. All standardsare subject to revision, and parties to agreementsbased on this International Standard are encouragedto investigate the possibility of applying the most re-cent editions of the standards indicated below,Members of IEC and ISO maintain registers of cur-rently valid International Standards.

ISO 3170:1988, Petroleum liquids — Manualsampling.

ISO 3171:1988, Petro/eum liquids — Automatic pipe-line sampling.

ISO 3696:1987, Water for ana/ytica/ /aboratory use —Specification and test methods.

ISO 4788:1980, Laboratory g/assware — Graduatedmeasuring cylinders.

ISO 6353-2:1983, Reagents for chemica/ ana/ysis —Part 2: Specifications — First series.

!S0 6353-3:1987, Reagents for chemica/ ana/ysis —Part 3: Specifications — Second series.

IS 1448 [P: 291

ISO 6246:1995

3 Definitions

For the purposes of

:2004

this International Standard, thefollowing definitions apply.

3.1 existent gum: Evaporation residue of aviationfuels, without any further treatment.

3.2 evaporation residue: Material that remains af-ter controlled heating under a flow or air or steam.

3.3 gum content, unwashed (non-aviation fuel):Evaporation residue of the product under test, without

any further treatment.

3.4 gum content, solvent-washed (non-aviationfuel): Residue remaining after the evaporation residue

has been washed with heptane and the washingsdiscarded.

4 Principle

A measured test portion of fuel is evaporated undercontrolled conditions of temperature and flow of airor steam. The resulting residue is weighed, and maybe subject to further treatment by solvent washingand further weighing.

5 Reagents and materials

During the analysis, unless othetwise stated, use onlyreagents specified in ISO .6353-2 and ISO 6353-3 iflisted there; if not, use reagents of recognized ana-lytical grade. Water where specified, shall be of aquality equivalent to grade 3 of ISO 3696.

5.1 Heptane, CHs(CHz)&Hs.

5.2 Toluene, CGH&Hs.

5.3 Acetone, CH3COCH3.

5.4 Gum solvent, a mixturetoluene (5.2) and acetone (5.3).

of equal volumes of

5.5 Air supply, filtered, at a gauge pressure of notgreater than 34,5 kPa.

5.6 Steam supply, free of oily residue and at apressure of not less than 34,5 kPa.

6 Apparatus

6.1 Balance, capable of weighing to an accuracy of0,1 mg.

6.2 Beakers, 100 ml of capacity, tall form, as iHus-trated in figure 1, individually permanently marked.

NOTE 2 It is expedient to arrange the beakers in sets, thenumber in each set being the number of beaker wells in theevaporating bath. The lowest-mass beaker in each setshould be reserved for use as the tare.

6.3 Cooling vessel, tightly covered, for cooling thebeakers before weighing.

NOTE 3 If a desiccator is used, a drying agent is not re-commended.

6.4 Evaporation bath, either a solid metal blockbath or a liquid bath, electrically heated and con-structed in accordance with the general principlesshown in figure 1, having wells and jets for two ormore beakers.

The rate of air/steam flow at the temperature of testfrom each outlet jet when fitted with the conicaladaptors shall be 1 000 ml/s * 150 ml/s. A liquidbath, if used, shall be filled to within 25 mm of the topwith a suitable liquid. Maintain the bath temperatureeither by means of thermostatic controls or by reflux-ing liquid of suitable composition.

6.5 Flow indicator, capable of indicating a total flowof air or steam equivalent to 1 000 ml/s for each out-let jet.

6.6 Sintered giass fiiter funnei, capacity 150 ml,with a maximum pore diameter between 150 pm and250 pm.

6.7 Steam superheater, gas-fired or electricallyheated, capable of delivering to the bath inlet the re-quired amount of steam at 232 “C + 3 ‘C.

6.8 Two thermometers, conforming to the require-ments in annex A.

6.9 Graduated cyiinders, capacity 50 ml -or 100 mland 2 Iitres, conforming to the requirements ofISO 4788.

6.10 Forceps, stainless steel, spade-ended.

6.11 Oven, capable of being maintained at 150 “C* 2 “c.

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IS 1448 [ P :29 ] :2004

ISO 6246: 1995

7 Assembly of air-jet apparatus

7.1 Assemble the air-jet apparatus as shown in fig-ure 1. With the apparatus at room temperature, adjustthe flow of air to a rate of 600 ml/s at one of theoutlets, with the remaining conical adaptors in pos-ition. Check the other outlets individually under thesame conditions for uniform air flowrate within therange of 600 ml/s + 90 mI/s.

NOTE 4 A total reading on a flow indicator (calibratedunder ambient conditions) corresponding to 600 rollst 90 ml/s at each outlet will ensure a flowrate of1000 ml/s * 150 ml/s at a temperature of 155 ‘C * 5 “C,provided that the pressure at the outlet of the flow indicatoris not greater than 34,5 kPa.

7.2 In order to set the apparatus in operation, heatthe bath until the temperature reaches 162 “C, andthen introduce air into the apparatus until the readingestablished in accordance with 7.1 is obtained on theflow indicator. Measure the temperature in each wellwith the thermometer (6.8) placed with the bulb rest-ing on the bottom of a beaker (6.2) in the well. Do notuse any well having a temperature that differs from155 “C by more than 5 “C for standard tests.

8 Assembly of steam-jet apparatus

8.1 Assemble the steam-jet apparatus as shown infigure 1.

8.2 In order to set the apparatus in operation, heatthe bath until the temperature reaches 232 “C. Oper-ate the superheater, and slowly admit dry steam intothe apparatus until a flowrate of 1 000 ml/s~ 150 ml/s per outlet is obtained. Regulate the tem-perature of the bath within the range 239 “C + 7 “Cand that of the superheater to provide a well tem-perature of 232 “C + 3 “C. Measure the temperaturewith the thermometer (6.8) placed with the bulb rest-ing on the bottom of a beaker (6.2) in the well. Do notuse any well having a temperature that differs from232 “C by more than 3 “C for standard tests.

8.3 Calibrate the flowmeter by successively con-densing the steam flow from each outlet and weigh-ing the total quantity of water recovered. Toaccomplish this, attach a copper tube to a steam out-let jet and extend the tube into a 2 Iitre cylinder (6.9)that has been filled with crushed ice and thenweighed. Exhaust the steam into the cylinder for ap-proximately 60 s. Adjust the position of the cylinderso that the end of the copper tube is immersed in thewater to a depth of less than 50 mm to prevent ex-cessive bat-k-pressure. Weigh the cylinder. The gain

in mass represents the amount of steam condensed.Calculate the steam flowrate, S, as follows:

s = (~ –ml) 1 ooo/kf

where

s is the flowrate of the steam, in millilitresper second, at 232 ‘C;

% is the mass, in grams, of the cylinder withthe condensed steam;

ml is the mass, in grams, of the cylinder andice;

k is the mass (0,434 g) of 1 000 ml of steamat 232 “C at atmospheric pressure;

t is the condensing time, in seconds.

8.4 Adjust the apparatus to give a steam flowrateof 1 000 ml/s for the outlet under test. Check the re-maining outlets for uniform steam flow. Makenecessary changes to individual outlets if the ratevaries by more than 150 ml of steam per second, re-cord the flowmeter reading qnd use this setting forsubsequent testing.

9 Samples and sampling

Samples for testing by the procedures described inthis International Standard shall be taken by the pro-cedure described in ISO 3170, ISO 3171 or an equiv-alent

10

10.1

national standard.

Procedure

Wash the beakers (6.2) including the tare, withthe gum solvent (5.4) until free of gu-m. Rinse thor-oughly with water and immerse in detergent cleaningsolution. The type of detergent and conditions for itsuse shall be established in each laboratory. The crite-rion for satisfactory cleaning shall be a matching ofthe quality of that obtained with chromic acid cleaningsolution on used beakers (fresh -chromic acid, 6 hsoaking period, rinsing with water and drying). Re-move the beakers from the cleaning solution bymeans of forceps (6.1 O) and handle only with forcepsthereafter. Wash the beakers thoroughly, first with tapwater and then with grade 3 water, and dry in theoven (6.1 1), controlled at 150 “C, for at least 1 h. Coolthe beakers for at least 2 h in the cooling vessel (6.3)placed in the vicinity of the balance (6.1).

NOTE 5 For the comparison of cleaning efficiency, visualappearance and loss in mass on heating the glassware un-der test conditions may be used. Detergent cleaning avoids

IS 1448 [ P :291:2004ISO 6246:1995

the potential hazards and inconvenience related to handlingcorrosive chromic acid solution. The latter remains as thereference cleaning practice and as such may function as analternative to the preferred procedure of cleaning with de-tergent solutions.

WARNING — Chromic acid is a health hazard. It istoxic, a recognized carcinogen as it contains Cr(Vl)compounds, highly corrosive and potentially haz-ardous in contact with organic materials. Whenusing chromic acid cleaning solution, eye pro-tection and protective clothing are essential.Never pipette the cleaning solution by mouth. Af-ter use, do not pour cleaning solution down thedrain, but neutralize it with great care owing tothe concentrated sulfuric acid present, and dis-pose of it in accordance with standard proceduresfor -toxic laboratory waste (chromium is highlydangerous to the environment).

Non-chromium-containing, strongly oxidizing acidcleaning solutions are also highly corrosive andpotentially hazardous in contact with organic ma-terials, but do not contain chromium which hasspecial disposal problems.

10.2 Select the required conditions for testing avi-ation and motor gasolines or aircraft turbine fuel fromtable 1 and set the apparatus in operation followingthe procedures of 7.2 or 8.2 as appropriate. If an ex-ternal preheater is used, regulate the temperature ofthe (vaporizing) medium to give the specified test welltemperature.

Table 1 — Test conditions

Operatingtemperature

Sampletype Vaporizing “cmedium

Bath Test well

Aviation and Atr 160to 165 150to 160

motor gasoline

Aircraft turbine Steam 232 to 246 229 to 235fuel

10.3 Weigh the test beakers against the tare beakerto the nearest 0,1 mg. When a single-pan balance isused, weigh the tare beaker as a blank. Record themass of each beaker.

10.4 If suspended or settled solid matter is present,mix the contents of the sample container thoroughly.Immediately filter a quantity of the sample, at atmos-pheric pressure, through the sintered glass funnel

(6.6). Treat the filtrate as specified in 10.5 to 10.7 in-clusive.

10.5 By means of the graduated cylinders (6.9), add50 ml of the sample to each beaker except the tare,using one beaker for each of the fuels to be tested.

Place the filled beakers, and the tare, in the evapo-ration bath (6.4). The elapsed time between placingthe first and last beakers in the bath shall be as shortas possible. When evaporating samples by means ofair, replace the conical adaptor as each individualbeaker is placed in the bath. When using steam, allowthe beakers to heat for 3 min before replacing theconical adaptor, which shall be preheated in the steamstream prior to attaching to the outlet. Centre theconical adaptors above the centre of the liquid. Takecare to avoid splashing when introducing the jet of airor vapour, as this could cause gum values to be inerror.

Maintain the temperature and rate of flow and allowthe test portions to evaporate for 30 min. Samplestested simultaneously shall have similar evaporationcharacteristics.

NOTE 6 In certain cases, duplicate testing is advisable todetermine precision.

10.6 At the end of the heating period, transfer thebeakers from the bath to the cooling vessel (6.3).Place the cooling vessel in the vicinity of the balancefor at least 2 h. Weigh the beakers in accordance with10.3. Record the mass of the beakers.

10.7 Segregate beakers containing residues fromproducts for which the heptane-insoluble portion ofthe gum is also required to be determined, and returnremaining beakers for cleaning and re-use.

10.8 To each of the beakers segregatedtogether with the tare beaker, add 25 ml ofand swirl gently for 30 s. Allow the mixturefor 10 min.

in 10.7,heptaneto stand

10.9 Decant and discard the heptane solution, tak-ing care to prevent the loss of any solid residue.

10.10 Repeat the extraction with a second 25-mlportion of the heptane, as described in 10.8 and10.9, Repeat the extraction a third time if the extractis coloured.

10.11 Place the beakers, including the tare, in theevaporation bath, maintained at 160 “C to 165 “C and,without replacing the conical adaptors, allow thebeakers to dry for 5 min.

5

“IS 1448 [P:29] :2004

‘ISO 6246:1995

10.12 At the end of the drying period, remove thebeakers from the bath, place them in the coolingvessel (6.3), and allow them to cool in the vicinity ofIhe balance for at least 2 h. Weigh and record themass of the beakers.

11 Calculation of gum content

11.1 Calculate the gum content, A, from the for-mula:

A = 2000 [(ml – ~) – (W – m4)]

where

A is the gum content, expressed as milli-grams per 100 ml;

ml is the mass, in grams,beaker plus residue;

% is the mass, in grams, ofafter treatment;

of the sample

the tare beaker

% is the mass, in grams, of the empty sam-ple beaker;

md is the mass, in grams, of the tare beakerbefore treatment.

11.2 If -a double-pan balance is used, with theweighings made against the tare before and aftertreatment, use the formula:

A=2000(~–n@

where

m~ = ml – W, in grams;

% = ~ – md, in grams.

12 Expression of results

12.1 For aviation fuels, express the results, to thenearest 1 mg/100 ml, as existent gum.

12.2 For non-aviation fuels, express the results, tothe nearest 1 mg/1 0.0 ml, as either gum content (un-washed) or gum content (solvent-washed), or both.

12.3 For all fuels, if the filtration step (10.4) hasbeen carried out before the evaporation, the word“filtered” shall follow the numerical value.

6

13 Precision

The precision, as obtained by statistical examinationof interlaboratory test results, is given in 13.1 and 13.2and illustrated graphically in figures 2 to 4.

13.1 Repeatability, i-

The difference between successive test results ob-tained by the same operator with the same apparatusunder constant operating conditions on identical testmaterial would, in the normal and correct operationof the test method, exceed the value below only inone case in 20:

r = 1,71 + 0,095x forline);

r = 0,5882 + 0,24%turbine fuel);

existent gum (aviation gaso-

for existent gum (aviation

r = 0,42x for gum content (unwashed);

r = 0,882 + 0,274 6x for gum content (solvent-washed);

where x is the average of the results being compared.

13.2 Reproducibility, R

The difference between two test results independ-ently obtained by different operators operating in dif-ferent laboratories on nominally identical test materialwould, in the normal and correct operation of the testmethod, exceed the value below -only in one case in20:

R = 2,60 + 0,126x for existent gum (aviation gaso-line);

R = 2,941 + 0,279 4X for existent gum (aviationturbine fuel);

R = 1,333x for gum content (unwashed);

R = 1,06+ 0,556 7X for gum content (solvent-washed);

where x is the average of the results being compared.

NOTE 7 The precision values given above for gum con-tent, both unwashed and solvent-washed, were obtainedon motor gasoline samples only, and therefore do notnecessarily reflect the values obtainable on other producttypes.

14 Test report

IS 1448 [P : 29] :2004

ISO 6246:1995

b) the type and complete identification of the prod-uct tested;

c) the result of the test (see clause 12);

The test report shall contain at least the following in- d) any deviation, by agreement or otherwise, fromformation: the procedure specified;

a) a reference to this International Standard; e) the date of the test.

I . -... .-,”,,,. ,“G. !o 5 10 15 20 25 30

Existent gum, mg per 100 ml

Figure 2 — Precision for existent gum

7

IS 1448 [ P :29 ] :2004

ISO 6246:1995

Figure

20

15

10

70

60

50

40

30

20

10

3—

10 20 30 40 50 60

Gum content (unwashed), mg per 100 ml

Precision for gum content (unwashed)

5,—

Motor gasoline

Figure 4 —

5 10 15 20 25 30

Gum content (so(vent-washed), mg per TOOml

Precision for gum content (solvent-washed)

IS 1448 [ P :291:2004

ISO 6246:1995

Annex A(normative)

Thermometer specification

A.1 Thermometer specification

The thermometer described in6.8 shall meet the re-quirements given in table A.1.

-r-i-a- n . “--. .?-- —--—-—i!-- AL- ——––—------ x.I ame H. I — nequlremems ror mermomeler Tor

the determination -of gum content by jetevaporation

Range, “C –5 to +400Graduation, ‘C 1

Immersion, mm 76

Overall length, mm 410 to 420

Stem diameter, mm 6,0 to.7,5

Bulb shape Cylindrical

Bulb length, mm loto15

Bulb diameter, mm 5,0 to 6,0

Length of graduated portion, mm 250 to 290

Distance from bottom of bulb tograduation at O “C, mm lootollo

Longer lines at each, “C 5

Figured at each, “C 10Expansion chamber See note 1

Scale error, ‘C 1 “C max. up to 301

1,5 “C max. over 301

NOTES

1 An expansion chamber is provided for relief of gaspressure to avoid distortion of the bulb at higher tem-peratures. It is not intended for the purpose of joiningmercury separation and under no circumstances shouldthe thermometer be heated above the highest tempera-ture reading,

2 Thermometer type ASTM 3C/lP 73C meets the aboverequirements.

A.2

If the

Emergent stem correction

average temperature of the medium surround-ing the emergent stem, measured by suitable means,

departs from the expected average temperature ofthe emergent stem as given in table A.2, appropriatecorrections shall be applied to the thermometer read-ing,

Table A.2 — Emergent stem correction

Thermometer Average temperature ofreading emergent stem

“c “c

o 19100 50

200 75300 89370 92400 94

( continued from second cover)

In case of ISO 3171, 1S0 6353-2 and ISO 6353-3, the Committee responsible for the preparation of thisstandard took cognizance of this Standard and decided that this is acceptable for use in conjunctionwith this standard.

For tropical countries like India, the Standard temperature and the relative humidity shall be takenas 27 t 2°C and 65 * 5 percent respectively.

In reporting the results of a test or analysis made in accordance with this standard, if the final value,observed or calculated, is to be rounded off, it shall be done in accordance with IS 2:1960 ‘Rules forrounding off numerical values ( revised )’.

Bureau of Indian Standards ,“

BIS is a statutory institution established under the Bureau of/ndian StandardsAct, 1986 to promoteharmonious development of the activities of standardization, marking and quality certification of

goods and attending to connected matters in the country.

Copyright

BIS has the copyright of all its publications. No part of these publications maybe reproduced in any

form without the prior permission in writing of BIS. This does not preclude the free use, in the course

of implementing the standard, of necessary details, such as symbols and sizes, type or grade

designations. Enquiries relating to copyright be addressed to the Director (Publications), BIS.

Review of Indian Standards

Amendments are issued to standards as the need arises on the basis of comments. Standards are

also reviewed periodically; a standard along with amendments is reaffirmed when such reviewindicates that no changes are needed; if the review indicates that changes are needed, it is takenup for revision. Users of Indian Standards should ascertain that they are in possession of the latestamendments or edition by referring to the latest issue of ‘BIS Catalogue’ and ‘Standards : Monthly

Additions’.

This Indian Standard has been developed from Doc : No. PCD 1 ( 1940 ).

Amendments Issued Since Publication

Amend No. Date of Issue Text Affected

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