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.

इंटरनेट मानक

“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda

“Invent a New India Using Knowledge”

“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru

“Step Out From the Old to the New”

“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan

“The Right to Information, The Right to Live”

“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam

“Knowledge is such a treasure which cannot be stolen”

“Invent a New India Using Knowledge”

है”ह”ह

IS 1223 (2001): Apparatus for Determination of Milk Fat byGerber Method [FAD 19: Dairy Products and Equipment]

IS 1223 : 2001

TR"6R~ GNT ~~ etr Cffff~m cf>~-~

(rf)t1'?7 TRtwr)

Indian Standard

APPARATUS FOR DETERMINATION OF MILK FATBY GERBER METHOD - SPECIFICATION

( Third Revision)

ICS 67.100.01

c(') HIS 200 I

BlJREAlJ ()F INlllAN STANDARDSMANAK BIIAVAN, 9 HA1-lAL)UR SIIAII ZAFAR MAH.G

NEW DELIII 110002

October 200 I Price Group 8

Reaffirmed 2009

AMENDMENT NO. I JUNE 2006TO

IS 1223: 2001 APPARATUS FOR DETERMINATIONOF MILK FAT BY GERBER METHOD­

SPECIFICATION

( Third Revision)

( Page 14, Section 6, clause 19.2.2 ) - Insert the following at the end ofthe existingtext:

'In case of a hand operated centrifuge, the temperature of the contents of thebutyrometer shall be taken after centrifuging by inserting a thermometer in abutyrometer after takingthe readingof the fat column. '

( Page 14, Section 6, clause 19.4.3, line 1 ) - Substitute 'Electric drivercentrifuge' for 'Centrifuge t •

( Page 14, Section 6, clause 19.4.3, line 7 ) - Insert the following at theend of the existingtext:

'In case of a hand operated centrifuge, speed is controlled by hand only andappropriate speed indicator shall be provided for governing the same. '

(FAD 19)

Rcprography Unit, BIS, New Delhi, India

Dairy Products and Equipment Sectional Committee, FAD 57

FOREWORD

This Indian Standard (Third Revision) was adopted by the Bureau of Indian Standards, after the draft finalizedby the Dairy Products and Equipment Sectional Committee had been approved by the Food and AgricultureDivision Council.

The dairy industry, trade and public analysts in the country prefer to use the Gerber method for rapid androutine deterrnination of fat in milk and milk products, especially when relatively large numbers of sampleshave to be analyzed at a time and electronic milk testers arc unavailable. The use of apparatus standardized andcalibrated according to the conditions and materials available in India and the adoption of uniform methods ofdetermination of fat are essential to obtain cornparablc results, within a reasonable degree of accuracy. It is inthis respect that this standard was originally published in 1958.

The standard was splited in three parts during first revision in )970. This was merged during the second revisionin 1982 The present revision, incorporates the following major changes:

a) Wall thickness and graduation marks thickness ofbutyrometers has been modified,

b) Material requirements for stoppers have been made more explicit,c) Safety requirements have been prescribed for centrifuge,

d) Recommendations on the use of centrifuges have been specified, ande) Additional type of butyrometers have been incorporated.

This standard comprises the following Sections:

a) Section I

b) Section 2c) Section 3

d) Section 4

e) Section 5

t) Section 6

g) Section 7

h) Section 8

ButyrometcrsStoppersPipettes

Automatic Measures

'nIt Measures

CentrifugesWater-BathGeneral

For the purpose of deciding whether a particular requirernent of this standard is complied with. the tinal value,observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance withIS 2:1960 "Rules for rounding off numerical values (revisedi', The number of significant places retained in therounded off value should be the same as that of the specified value in this standard.

IS 1223 : 1001

Indian Standard

APPARATUS FOR DETERMINATION OF MILK FATBY GERBER METHOD - SPECIFICATION

( Third Revision)

2 REFERENCES

The Indian Standards listed below contain provisionswhich through reference in this text. constitute

'lvisions ofthis standard. At the time ofpublication,..~ editions indicated were valid. All standards are

subject to revision. and parties to agreements basedon this standard are encouraged to investigate thepossibility of applying the most recent editions of thestandards indicated below:

~ ~)COPE

This standard prescribes requirements for thebutyrometers, stoppers, milk pipettes, amyl alcoholpipettes, automation measures, tilt measures,centri fuges and water-bath requ ired for the deter­mination ofpercentage of fat in whole milk, skim milk,separated milk. partly skim milk, butter milk, cream,butter, cheese. ice cream, condensed milk, evaporated(unsweetened) milk and dry milk powder by the Gerbermethod.

ts No.57 : 1989

302 (Part I) :

TitleRed lead for paints and otherpurposes (second revision)Safety of household and similar

IS No.1979

1224

(Part I) : 1977(Part 2) : 1977

2303 (Part 1/Sec I) : 1994

2932 : 1994

4426 : 19Q2

5216

(Part I): 1982(Part 2) : 1982

5623 : 1970

Titleelectrical appliances: Part I Generalrequirement (fifth revision)Determination of milk fat by theGerber method :Milk (first revision)Milk products (first revisionsMethod of grading glass foralkalinity: Part 1 Ilydrolyticresistance, Section 1 Hydrolyticresistance ofglass grains at 98°C ­Method of test and classification(first revision)Enamel, synthetic, exterior (a)undercoating (b) finishing (secondrevision)Methods of sampling laboratoryglassware (first revision)Guide for safety procedures andpractices in electrical work:General (first revision)Life saving techn iques (firstrevision)Method of determination ofcoefficient of linear thermalexpansion of glass

SECTION 1 BUTYROMETERS

3 TYPES

Eleven types ofbutyrometcrs are specified as follows:

a) Butyrometer, 6 percent For testing wholescale milk and evapora-' ..'yrometer, 8 percent rated (unsweet-

c ened) milk

rometer, 10 percent

.! iuantity, 0.5 percent

e) But}', ... neter, 4 percent scale

t) Butyrometer, 70 percentscale

For testing skimmilkFor testing sepa­rated milk, partlyskim milk andbutter milkFor testing cream

g) Butyrometer. 40 percent For testingscale cheese

h) Butyrometer, 20 percent For testing dryscale powder milk powder

j) Butyrometer, 20 percent For testing icescale cream and con-

densed milk

k) Butyrometer, 90 percent For testing butterscale

01) Butyrometer, 40 percent For testing dryscale milk powder

4 REQUIREMENTS

4.1 Material

4.1.1 The butyrometer shall be made from clean

IS 1223 : 2001

borosilicate glass (Type 1)with a co-efficient of linearthermal expansion of 33x)O-'/oC (see IS 5623) andshall be resistant to chemicals and to the thermalshocks incidental to the method.

NOTE- The hutyrometcrsshall bewell annealedand free fromstones, blisters cracks and as far as possible from bubbles andother visibledefects.

thickened by an outside rim at the top to a maximumof2.5 mm.

4.4.2.1 The thickness of the rim shall be measured bytaking half of the difference between the outsidediameter of the rim and the outside diameter of theneck.

4.1.2 Limit for Alkalinity

When graded according to the method prescribed inIS 2303 (Part l/Sec 1), the butyrometers shall conformto Type I of the glass.

4.2 Shape

4.2.1 The internal transitions from body and bulb tothe flat tube shall be such as to allow free flow of fat.The axis of the bulb, flat tube body and neck shall bein line.

4.2.2 The butyrometers may have circular or flatgraduated tube.

4.3 Dimensions

Dimensions of the butyrometers shall be as given inTable I.

Table 1 Dimensions or Butyrometer!

4.4.3 Corrugated Neck

4.4.4 The corrugations shall be in places at right anglesto the axis of the butyrometers and not from a spiralproducing a screw thread. The internal diameter ofthe neck specified in Table 1 shall be measured at thenarrow parts of the corrugations.

4.5 Body

The capacity of butyrometers between the base of theneck and the 0 percent graduation mark (that is,between the points A and B in Fig. I to 5) known ascapacity of the body, shall be as shown for theappropriate butyrometer in Table 2.

4.6 Graduated Tube

The graduated tube shall be of the flat scale type (see

Fig. 1. 2, 3 and 4). However, circular tube may also beused (see Fig. 5). The back surface of the tube shallnot be frosted.

SI No. Particulars Dimtnsions(mm)

4.3.1 The butyrorneters are illustrated in Fig. 1 to 5.Dimensions other than in Table I for the butyrometerswhich are shown. in Fig. I to 5 arc for informationonly, but there should not be any gross departure fromthese.

4.4 Neck

4.4.1 The neck of the butyrometers shall be either ofplain type or of corrugated type (see Fig. I to S).

4.4.2 In the case ofplain neck, it should preferably be

4.9 Length of Scale

The total length of the scale, from the 0 percentgraduation mark to the graduation nearest the bulb,shall be not less than the figure shown for theappropriate butyrometer in Table 2.

4.10 Position of SeaIe

The graduated tube shall remain uniform in cross­section for at least 3 mm beyond each end ofthe scale.

4.7 Bulb

4.7.1 The capacity of the bu Ib of the butyrometers upto the graduation mark nearest to the bulb (betweenthe points C and D in Fig. 1 to 5) shall be at least1.5 ml. The bulb shall be tapered as shown in Fig. Ito 5 and the inside of the buIb shall he so shaped thatfat is allowed to flow freely from the bulb to thegraduated tube, when the butyrometer is inverted.

4.7.2 A small patch of matt surface shall be providedon the bulb, on which temporary markings may beplaced when necessary.

4.8 Graduations

The basis of graduation shall be as shown for theappropriate butyrometer in Table 2.

(3)

190:i- 5

14.5 1. I 5

18

1.2

15

17.0 ± () 5

11.01; O.S

25

(2)(I)

i) Overall length

ii) Lengthof the neck

iii) Internal diameter of the neck (see4.4)

a) For cheese vangolicmethodb) for others

iv) External diameter of the body. Maxv) External diameterof the bulb for butyrorneters

oro.s. 4. 6. 8 and 10percent scales. Maxvi) External diameter ofthe bulb for testing cream

and cheese. Max

vii) Wall thickness of graduated portion, Min

viii) Wall thickness forother than graduatedportion. Mtn 0 Q

NOTE - For wall thickness at joints and at curved portions. afurther tolerance of - 0.1 mm is permitted.

2

IS 1223 : 2001

• PERCENT 6 PERCENTSCALE SCALE

~!SECTION XX ,..

RING-TYPE NECIC

A

n-ote-s 10

10 PEACENT SCALE

1ftN+1II';.,•

'"Itt+.II' II'~ r-•

1fttlo•

...----~~~+---D

All drmcnsrons 111 nulhrnetres

FIG. I BUTYROMETER, 6,8 AND 10 PIRtLNI SCALi

4.11 Graduation Marks

4.11.1 The graduation Marks shall be fine, clearpermanent lines of uniform thickness and there shallbe no evidence of irregularity in their spacing.

4.11.2 The graduation marks shall be lying in planesperpendicular to the longitudinal axis of the graduatedtube. The thickness of the graduation marks, shall notbe less than 0.1 rnm and not more than 0.2 mrn foretched but for screen printed graduation marks,the thickness of graduation marks shall be maximum0.25 mm.

4.11.2.1 The thickness of the graduation rnarks maybe determined visually by comparing them with thelines of the desired thickness drawn on a paper.

4.12 Range of Scale and Scheme of Graduation

4.12.1 The range and graduations of the scale shall

be in accordance with the provisions of Table 2 andFig. 1 to 5. The numbered graduation mark shall becarried completely across the front face of thebutyrometer. The shortest graduation marks shall beat least 3 mm in length. The graduation marks ofintermediate length shall project equally both to theI ight and to the left of the shortest graduation marks,at a distance of at least I mm.

4.12.2 For circular tubes graduation mark should beas follows:

a) The main number graduation mark shouldbe carried on complete round of the tube;

b) The half graduation mark should cover 3/4of the round tube; and

c) The smallest graduation marks should coverat least 1/4 of the round tube.

3

IS 1223 : 2001

Table 2 Capacities, Scales and Tolerances for Butyrometen(Clauses 4.5, 4.8, 4.9. 4.1.2.1, 4.13 and 4.14)

SI P~rtent Quantity of Ba.ls of Capacity Length Graduated Graduated Numbered Error Pereent,No. Stair 1\1aterial Graduation ofRody of Scale, at each of Interme- a' I of Fa. lor

Tested in ml loml Min Percent diate Each 100 I or SampleLength at Percent MIIX

EachPercent

(I) (2) (3) (4) (5) (6) (7) (8)mm

i) 6 1075 ml 0.125 corresponds 20 S±O S 65 01 OSto 1%fat

ri) 8 I07Smi 0.125corresponds 20 5±0 5 70 o I OSto 1% fat

iii) 10 I075ml o125corresponds 20 S±O S 75 01 05to 1% fat

iv) 4 I075ml 0.125 corresponds 20 5±O 5 60 005 01to 1% fat

v) O~ 21 Sml o125 corresponds 43 5iO S 20 002 01to 0 OS,. fat

vi) 70 5g 3 974 corresponds 21 5±O 5 6~ SOto 7()OAt fat

vii) 40 3g I 350 corresponds 21 S±O S 60 ~O

to 400At fat

(9) (10)

005

0.05

oos

01 001

01 001

10 050

10 0 so

4.13 Numbering of Graduation Lines

The numbering of graduation lines for the differenttypes of butyrometers shall be as shown in Table 2.The numbers of the scale shall be permanent andclearly legible, and each shall be placed immediatelyabove the graduation mark to which it refers and tothe right ofthe axis ofthe scale, when the butyrometeris placed vertically with the bulb uppermost. Thepercentage symbol (%) should be above the uppermostnumber. as shown in Fig. 1 to 5.

Nf)TE - 1 he graduation mark may be refilled by the methodgiven in Annex A

4.14 Tolerances

The maximum error allowed at any point on the scaleand also the maximum difference between the errorsat any two points on the scale shall be in accordancewith the figures given for the appropriate butyrometerin Table 2. A recommended method of calibration isdescribed in Annex B.

5 MARKING

Each butyrometer shall have permanently and legiblymarked on the body;

a) Quantity of material to be used, that is,'10.75/21.5 ml' milk, 'S g' cream or '3 g'cheese, as the case may be;

b) 65°C;

c) Maker's name; and

d) Identification number.

4

.....--..........H'11S melx.

-SECTION XX

LARGE BULB

A STRENGTHENINGRIM

~......6--- lD 11.010.5

Alldimensions inmillimetres

FIG. 2 BUfVROMETER (DOUBLE QUANTITY), 0.5 PERCf..NT

IS 1223 : 2001

RING--TYPE NECK

~SECTION XX

1I-0!O-S 10

MattSurface

25 max.

c--E=o~

E1ft fW)

.ft+1II'.N~

-.-.-------............--0

an+.o~

All drmenvions In nullrmctrcs

FIG. 3 B1J1' ROMF II R, 4 PERCt-Nl

5

IS 1113 : 2001

RING-TYPE NICK

~SECTION XX

~ lIoQ!O-S ID

25max.

EII'•

c.-

c--~+1aftI-.•

1ft+1o~ B

All dimensions in millimetres.

Flu. 4 BUTYROMETER, 70 PERCENT

6

IS 1223 : 2001

All drmensions In millimetres

FIG. 5a BUTYROMETER, 40 PI-Rei NT

--..- '1t"'----_..... 't:~--t...---_- .. &1\

~

i4»ext.25rnu.

z

y

NECK

BODY

-$- XiSECTION x-x

GRADUATED TUBE

MATT SURFACE

00 18

A

.....--~-OD 21 mdx.

x1. -

$0&=

-=60 oz= SECTION XX-

1BOsS

All dimensions in rmllrmetres

FICJ. 5b Btl fYROMETER, 90 PI Rl LNT

SECTION 2 STOPPERS

6 TYPES

The following two types of stoppers suitable for uscwith the butyrometers are recommended:

a) The double-ended stoppers (Fig. 6); andb) 'The lock stoppers (Fig. 7).

7 REQUIREMENTS

7.1 Shape

7.1.1 The double ended stoppers shall be used withbutyromctcrs having corrugated necks, and lockstoppers shall be used with butyrometers having plainnecks.

7.1.2 'The construction of the double ended stoppersshall be such that they may be screwed intobutyrorneters until the widest part is at least level withthe top of the neck.

7.2 Material

Ihe stoppers shall be made from acid resistant softrubber having 38 ± 5 international rubber hardnessdegrees. The disc, ring and collar may be made ofbrass, aluminium alloy or zinc.

7.3 Dimensions

The minimum thickness of brass ring shall be

7

IS 1223 : 2001

0.315 mm and for disc and collar, the minimumthickness shall be 0.710 mm. The length of metalcollar shall be 10 mm with a maximum tolerance of± 1.0 mm. The other dimensionsofboth types as givenin Fig. 6 and Fig.7 are for guidance only.

7.4 Lock stoppers shall be tested for elasticity by thetest method prescribed in Annex C.

8 MARKING

name/tradenameand each carton shall be markedwiththe following information:

a) Manufacturer's name or trade name, if any;

b) Type ofstopper;

c) Number of stoppers;

d) Batch number or Code number; and

e) Date of manufacture.

Each stopper shall be marked with the manufacturers

t=,1~6r:

--.....----.. to

u·s Dla

Alldimensions inmillimetres.

FIG. 6 DOUBLE-ENDE.I> RUBBER STOPPER

MEtAL DlIC

DISC__-- 22 10 !~;t

LOCK STOPPER

__--- ,. -------1M

KEY FOR LOCI< STOPPERr- COLLAR

BRASS RINGRUBBER STOPPER

BAll OF METAL.GLASSORPLASTlC<t>8m

All dimensions in millimetres.

FIG. 7 LOCK STOPPER AND KEY

8

IS 1223 : 2001

SECTION 3 PIPETTES

9 TYPES

The following two types of one-mark pipettes arespecified:

a) IO.75-ml pipette for milk, andb) I-ml pipette for amyl alcohol.

10.3 General Design

The general design ofthe pipettes shall be as illustratedin Fig. 8 and 9. The pipette shall be symmetrical aboutits central axis, that is, there shall be only one axis forthe suction tube, bulb and delivery tube and it shallform the central axis of the pipette.

20t5

GRADUATIONMARK

_.--1SeS! 1·0 •

-.-- 6·StO-S.

125!:30

60!:10

360t20

10.75 ± 0.03 ml

1.00 ± 0.05 ml

a) Milk pipette

b) Amyl alcohol pipette

10.1.1 Limitfor Alkalinity

When graded according to the method prescribed inIS 2303 (Part I/Sec 1), pipettes for amyl alcohol shallconform to Type 1 of the glass.

10.2 Capacity

The capacity of the pipettes shall be determined bythe volume of water at 27°C expressed in millilitresdelivered by the pipettes when emptied as describedin Annex D. The capacity so determined shall bewithin the following limits:

10 REQUIREMENTS

10.1 Material

The pipettes shall be made from stout walled glasstubing. Alternatively, milk pipette shall be made usinga one piece capillary tube.

NOTE- The pipettesshallbewellannealedand free fromstones,blisters. cracksandas faraspossible from bubbles andothervisibledefects.

10.4 Suction Tube

The top of the suction tube shall be ground off smoothand square with the axis of the tube, The outer edgeofthe top of the suction tube shall be slightly levelled.

10.4.1 The suction tube shall have a uniform andcircular cross-section at place of the graduation markand also above and below the graduation mark for alength of not less than 20 mm.

10.S Graduation Mark

The graduation mark shall be a fine, clean, permanentline of uniform thickness, completely encircling thesuction tube and lying in a place perpendicular to the

Alldimensions inmillimetres.

FIG. 8 A TYPICAL 10.75 ml MILK PIPErTf

axis of the suction tube. The etched graduation markmay preferably be filled with a black medium.

10.6 Bulb

The central portion of the main bulb of the milkpipettes shall be cylindrical and the two ends shallmerge gradually into the suction and delivery tubes asshown in Fig. 8. The safety bulbs on the suction tubeof amyl alcohol pipettes shall be shaped as shown inFig. 9.

9

IS 1223 : 2001

J·si e-s 10

FIG. 9 A TYPICAL I ml AMYL ALCOHOL PIPETTE

10.7 Delivery Jet

The jet ofthe delivery tube shall be made with gradualtaper, the taper at the end being slight so that there isno sudden constriction at the orifice. The capillary jet(reinforced as shown in Fig. 10) is preferable. Theend of the jet shall be ground off smooth and squarewith the axisof the pipette. The outer edge of the endof the jet shall be slightly levelled.

10.8 The pipettes shall also conform to the dimensionsgiven in Table 3.

t 0.8. t Other dimensions of the pipettes if shown inFig.8 and 9 are for information only, but there shouldnot be any gross departure from these.

10.9 Delivery Time

10.9.1 It is the time occupied by the outflow ofwater,when determined in the following manner.

10.9.2 Clamp the pipette in a vertical position. Fill itwith water and make a setting on the graduation markas described in Annex D. Place a beaker beneath thepipette and incline slightly so that the tip ofthe pipetteis in contact with the inside wall of the beaker. Takeaway the finger from the top of the pipette and start astopwatch simultaneously. Observe the motion of thewater surface down the pipette and when the meniscuscomes to rest a little above the lower end of the jet,stop the watch. The time recorded by the stopwatchshall be the delivery time of the pipette.

10.9.3 The delivery time thus determined shall bewithin the following limits:

JOt-2 OD

2+1o2

Alldimensions inmJllirnetres

o+to!

oN..o'"~

Table 3 Dimensions of Pipettes«(;'/ause 10.8)

SINo.

Particulars Dimensions in mm

(I) (2)

i) Totallengthii) Length oftbe suction tube

iii) Length of the tube above the safety bulbiv) Length of the tube below thesafety bulbv) Length of thedelivery tube

vi) Length of the tapered portionofdeliverytube formingjetvii) Distanceofgraduationmark

viii) Distanceof graduationmark from the top ofthc suction tubeix) Distance between thegraduation mark andthebulb, MI"x) Externaldiameterof the suction tube and the deliverytubexi) Internaldiameterofthe suction tube

xii) Externaldiameterof the main bulbxiii) External diameterof thesafety bulbxiv) Lengthof themain bulbxv) Wall thickness

NOTE- For wall thickness atjoints, curved portionsand at graduatedportions,a furthertoleranceof - 0 1mm is permitted.

10

IS 1223 : 2001

Alldimensions inmillimetres.

FIG. 10 SUITABLE SHAPES FOR JET

a) Milk pipette - 7 ± 2 seconds; andb) Amyl alcohol pipettes - not more than

3 seconds.

NOTE - The delivery time of a pipette can be adjusted bymanipulatingthe diameterof theorificeof thejet.

11 MARKING

Each pipette shall have the following informationpermanently and legibly marked on it:

a) Indication of the use of the pipette, namely,'Milk' or 'Amyl Alcohol', as the case maybe;

b) Capacity, namely, '10.75 ml', or '1 ml', asthe case may be;

c) Temperature of calibration, namely, 27°C;

d) Maker's name; and

e) Identification number.

SECTION 4 AUTOMATIC MEASURES

12 TYPES

Automatic measures shall be of two types, namely:

a) Automatic measure for sulphuric acid, andb) Automatic measure for amyl alcohol.

These shall be of the type illustrated in Fig. II and 12.

13 REQUIREMENTS

13.1 Material

13.1.1 The automatic measures shall be made fromclear glass. They shall be well annealed and free fromstones, blisters, cracks and as far as possibIe frombubbles and other visible defects.

13.1.1.1 Limit for alkalinity --- When gradedaccording to the method prescribed inIS 2303 (Part 1/Scc 1), the automatic measures shallconform to Type I of the glass.

13.2 Capacities

Automatic measures shall have the followingcapacities:

a) Automatic measure for sulphuric acid - Ilitre

b) Autornatic measure for amyl alcohol .-- 500or 250 ml.

I 1

13.3 Volume Delivered

The volume delivered by the automatic measures shallbe as follows:

a) The volume of distilled water in 5 seconds at27°C by the automatic measure for sulphuricacid shall be not less than 9.75 ml and notmore than 10.25 ml.

b) The volume of distilled water delivered at27°C in 3 seconds by the automatic measurefor amyl alcohol shall be not less than 0.95 mland not more than 1.05 ml.

c) For a period of 5 seconds after closing thestopcock of the automatic measure, no dropof its contents shall fall down the jet.

14 MARKING

Each automatic measure shall have the followinginformation permanently and legibly marked on it:

a) The inscription ·90 percent Sulphuric Acid'or 'Amyl Alcohol', as the case may be;

b) The nominal capacity' 10 ml' in the case ofsulphuric acid and' 1 rnl' in the case of amylalcohol;

c) Maker's name; andd) Identification number.

IS 1223 : 2001

CAPACITY 250mlOR

SOOml APPROX

AIR NLET THROUGHHOLES IN NECK ANDstOPPER

VIEW SHOWING SPLITPIN TO FIX KEY INBARREL OF STOPCOCK

FIG. 12 AUTOMATIC MEASURE FOR DELIVERING

I ml OF AMYL ALCOHOL

All HOLEIN .aRReL

AI. INLlt TMIQUONMOL I S IN NlCI( AND'10"&11

caPACITY

'011 I'.'

ItVII!1t cap10 ". ICIY'N la.IIL O'STOPCocK

FIG. II AUTOMATIC MEASURE FOR DELIVERING

10 ml OF SULPHURIC ACID

SECTION 5 TILT MEASURES

15 TILT MEASURES

Tilt measures shall be of the following two types:

a) Tilt measure for sulphuric acids (see Fig. 13);and

b) Tilt measure for amyl alcohol (see Fig. 14).

glass. They shall be well annealed and free from stones,blisters, cracks and as far as possible from bubblesand other visible defects.

16.1.2 Limit for Alkalinity - When graded accordingto the method prescribed in IS 2303 (Part I/Sec 1),tilt measures shall conform to Type 1 of the glass.

16 REQUIREMENTS

16.1 Material

16.1.1 The tilt measures shall be made from clear

16.2 Capacity

The capacity of the tilt measures shall be within thelimits given in 16.2.1 and 16.2.2.

12

IS 1223 : 2001

Alldimensions inmillimetres.

FIG. 13 10 ml SULPHURIC ACID TII.T MEASURE

All dimensions in millimetres.

FIG. 14 1 ml AMYL ALCOHOLTILT MEASURE

16.2.1 Till Measures for Sulphuric Acid at 27°C ­10.0 ± 0.25 ml.

16.1.2 Tilt Measures for Amyl Alcohol at 27°C ­1.0 ± 0.05 ml.

16.3 Dimensions

The dimensions of tilt measures shall be as illustrated

13

in Fig. 13 and 14.

16.3.1 The tilt measures shall be complete with hardrubber bung. For sulphuric acid" hard rubber bungshall be acid resistant.

17 MARKING

Each tilt measure shall have the following information

IS 1223 : 2001

permanently and legibly marked on it:

a) The inscription '90 percent Sulphuric Acid'or •Amyl Alcohol', as the case may be;

b) The nominal capacity' 10 ml' in the case of

sulphuric acid and' 1 ml' in the case of amylalcohol;

c) Identification number; andd) Maker's name.

SECTION 6 CENTRIFUGES

18 GENERAL

The centrifuges may be hand-driven or electric driven.

19 REQUIREMENTS

19.1 The materials used for construction of variousparts of the centrifuge shall be such that these shallbe capable of withstanding the maximum stress fordesired purposes and shall have adequate corrosionresistance under the conditions of service.

19.2 Construction

19.2.1 The construction ofthe centrifuge shall be suchas would allow the operator to take the butyrometerby the bulb from the centrifuge without disturbing theposition of the fat column after centrifuging. It shallpreferably be of the vertical loading type.

19.2.2 The design of the centrifuge shall be such thatthe temperature of the contents of the butyrometersafter centrifuging is between 30°C and SO°C.

19.2.3 The head shall be easy to dismantle in case ofbreakage of butyrometers.

19.2.4 Shape of Buckets

The buckets should preferably have a flat bottom.

19.2.5 Working Angle

When assembled in the clips, the butyrometers shallslope slightly downwards towards the rim of thecentrifuge.

19.2.6 Speed Indicator

The centrifuge shall be provided with a speed indicatorwhich should indicate the number of revolutions perminute. The speed indicator shall have a maximumtolerance of -t:50 rev/min in its reading.

19.2.7 The centrifuge shall be adequately balanced soas to run smoothly at the specified speed.

19.3 Speed

The centrifuge shall be capable of producing within2 minutes when fully loaded, a relative centrifugalacceleration of350 ± 50 g (acceleration due to gravity)at the outer end of the butyrometer stopper. This

14

acceleration is produced by centrifuges with thefollowingeffective radius(horizontaldistance betweenthe centre of the centrifuge spindle and the outer endof the butyrometer stopper) if operated at the speedindicated against each:

Effective RevolutionsRadius per Minutes

mm240 1 140245 J 130250 1 120255 I 110260 1 100 ± 70 rev/min265 1090270 1080275 1070300 1020325 980

NOTE - The relative centrifugal acceleration produced in acentrifugeis givenby the followingformula.

1 12 x I 0 ~ RJV2whereR effectivehorizontalradius in mm,andN speed in revolutionsper minute

19.4 Safety Requirements

19.4.1 Centrifuge shallbe surrounded by a casinghavinga strength sufficient to ensure containment within thechamber of all debris which would be generated ifdisruptions of the rotationassemblytakesplace from themechanical condition of the assembly. All rotating!movingparts to be enclosed in a protective cover.

19.4.2 Electric driven centrifuge shall be equippedwithdevicesdesigned to ensure that it cannot be starteduntil doors covers, lids and/or guards have been closedand secured and that access cannot subsequently begained until linear and rotational motion have ceased.

19.4.3 Centrifuge shall be provided with a speedcontrol and an over speed prevention device. For speedcontrol, where a centrifuge is fitted with a frictionbrake, an interlock shall be provided to prevent thecentrifuge from being set in motion until the brake isreleased. The application of any such brakes shallautomatically isolate the main drive mechanism.

19.4.4 The Electric centrifuge shall comply with theelectrical safety requirements as laid down underIS 302 (Part 1), IS 5216 (Part 1) and IS 5216 (Part 2).

19.4.5 The manufacturer shall supply with eachcentrifuge an instruction manual laying down safetyrequirements to be observed during installation andoperation.

20 RECOMMENDATIONS ON THE USE OFCENTRIFUGES

20.1 Introduction

When running, a centrifuge has considerable kineticenergy and even a small 'bench centrifuge' notcomplying with the safety requirements can expressdebris, or even move bodily, for a distance of severalmetres in the event of mechanical failure. Whileconsiderable effort goes into the design andconstruction of centrifuges to try to minimize thehazards, sensible usc is also important for the safetyof operators and others in the laboratory.

20.2 Installation

It is essential that centrifuges are fixed to the workingsurface, following the specifications andrecommendations of the manufacturer for suitablefixings and fixing details. Care should be taken toensure that working surface and its substrateare strongenough to withstand the maximum forces of rotationand translation expected to act on the fixings in theevent of a disruption of the rotation assembly. Acentrifuge may move abruptly in the event of such adisruption, inspite of the fixings, but the distance willbe limited if the centrifuge is correctly fixed.

20.3 Operation

20.3.1 Distribute the load symmetrically around therotation assembly so that it is evenly balanced andcomplies with the manufacturers instructions in thisrespect. It is essential that the balancing buckets carryan identical load and in particular are filled with aliquid of density not grossly dissimilar to that beingcentrifuged.

20.3.2 Select a centrifuging speed, subject to themaximum recommended by the manufacturer. Follow

15

IS 1223 : 2001

the manufacturers instructions for starting, increasingspeed and stopping the centrifuge.

20.3.3 Allow the rotation assembly to come to restbefore attempting to open the centrifuge lid. Neverattempt to slow down the head by hand.

20.3.4 Any acid and milk spill over in the centrifugeshould be removed immediately, followed by dryingthe inside of the centrifuge chamber.

20.4 Procedures to be Adopted After 8 Disruptionof the Rotation Assembly

20.4.1 Whenevera mechanical failure (other than thesimple breakage of sample container) of any part ofthe rotation assembly is suspected to have occurred,the procedure detailed in 20.4.2 to 20.4.4 should befollowed.

20.4.2 Immediately isolate the centrifuge from theelectric supply. Do not attempt to open the centrifugechamber until at least 20 to 30 min after all motionhas paused.

20.4.3 Avoid moving all defective and damagedcomponents, unless it is utmost essential and retainall components and debris for inspection by themanufacturer's representative.

20.4.4 Do not use the centrifuge or the rotationassembly again until all necessary repairs andreplacements have been completed and themanufacturer's representative has given an assurancethat its safety is not impaired.

20.5 Training of Operators

Training in the operation of the centrifuge should becarried out for all operators of the centrifuge beforethey are permitted to use the centrifuge.

21 MARKING

Each centrifuge shall have the following informationpermanently and legibly marked on it or in a platewhich is permanently fixed to it:

a) Manufacturer's name or trade-mark, and

b) Effective radius and speed (19.3.1).

IS 1223 : 2001

SECTION 7 WATER-BATH

11 REQUIREMENTS

22.1 Material

Water-bath shall be made of suitable material suchthat these shall be capable of withstanding themaximum stress for desired purpose and shall haveadequate corrosion resistance under the condition ofservice.

22.2 Temperature

Water-bath shall be capable of being maintained at65 ± 2°C. It shall also carry a suitable thermometer.

21.3 Shape

Water-bath shall be of sufficient depth as to supportthe butyrometer in vertical position with their scalecompletely immersed. The bath shall be fitted withhorizontal perforates plates to hold the butyrometer.

23 MARKING

a) Manufacturer's name or trade name, if any;and

b) Batch No. or Code No. or Identificationmarking.

SECTION 8 GENERAL

24 GENERAL

The scale of sampling of butyrometer, pipettes,automatic measures and tilt measures and method ofselection shall be as prescribed in IS 4426.

25 MARKING

25.1 Butyrometers, stoppers, pipettes, automaticmeasures, tilt measures shall be marked as describedin the marking clause of the relevant section for eachtype of apparatus.

25.1.1 Each butyrometer, pipette, automatic measure,tilt measure, centrifuge, water-bath and carton(see 4.1) containing stopper may be marked with theBIS Certification Mark.

26 PACKING

Butyrometers, pipettes, automatic measures, tiltmeasures, centrifuge and water-bath may be packedas agreed to between the purchaser and the supplier.Stoppers shall be packed in suitable cartons.

ANNEXA

(Clause 4.13)

DETAILS OF REFILLING GRADUATED MARKS

A-I MATERIAL

A-I.I Full Gloss Hard Drying Synthetic EnamelP.O. (Post Office) Red - Conforming to IS 2932.

A-I.l Lead Oxide Red - Conforming to Type 'A'of IS 57.

A-l PROCEDURE

Remove previous paint or colour in the marks, ifany,

16

by using thinner or with a pointed needle. Apply verylittle enamel paint, with finger tip, on the graduatedmarks. Rub the paint on the marks gently 4 or 5 timestill every mark comes in contact with paint. Wipe otTvery gently with clean cotton cloth, the paint on theapparatus leaving enamel paint on the marks only.Apply red lead oxide with cotton swab on the graduatedmarked portion (previously applied with paint) 3 or 4times. Clean gently with cotton cloth and removeunwanted powder from the apparatus.

IS 1223 : 2001

ANNEXO

(Clause 4.14)

RECOMMENDED APPARATUS AND METHOD FOR CALIBRATING THE SCALESOF GERBER BUTYROMETERS

8-1 APPARATUS

8-1.1 Mercury pipette (see Fig. 15) has been found tobe suitable for calibrating the scales of butyrometers.It has been designed to deliver 0.312 5 ml of mercurywithin ±O.OOO 3 ml, but pipettes to users' ownrequirements can be constructed on the same principlesby suitably modifying the capacity of the bulb. Thepipette is made of glass to the dimensions given inFig. 15. Dimensions marked by an asterisk areimportant and should be closely reproduced, ifconsistency of delivery is to be attained otherdimensions are given for guidance only.

8-1.2 The automatic zero depends for its action onthe closing of the top of the tube ~ FE' by the innersurface of a spherical glass cap. The cap is an easysliding fit on ~ FE" and is of sufficient mass to retainits seating on 'E' when the reservoir is suitably filledwith mercury.

8-1.3 The delivery terminates at the bottom, 'H', ofthe capillary ~Cil~' where the bore opens out sharplywithout constriction.

8-1.4 The rubber connections at Band D are employedto facilitate cleaning.

8-1.5 The apparatus is f lied as follows:

8-1.5.1 With the stop-cock S, closed, the reservoir, Ais filled with mercury and some ofthis enters the upperpart of the filling tube B('D, but the capillary portion,CD remains empty. The stop-cock S, is then cautiouslyopened and the mercury is allowed to run into thepipette with the stop-cock S., open until mercuryemerges from the orifice o. prh'"'e stop-cock 51 is thenclosed and SI still being open, the pipette filis to theautomatic zero E, when the flow of mercury into thepipette ceases. Any drop of mercury adhering to thejet is removed, and the stop-cock SJ is closed at anyconvenient time prior to delivery. Delivery is effectedby merely opening 52 . The desired quantity ofmercurythen flows from 0" and delivery, which occupies ratherless than 10 seconds, terminatcs automatically. Thestop-cock S:! is then closed and any drop of mercuryadhering to 0 is removed as part of the deliveredvolume. The reopening of'S, allows the pipette to refillin preparation for a further delivery.

8-1.5.2 The mean determined capacity of the pipetteshould not differ from the capacity inscribed on it bymore than ± I part in 1 000, of the inscribed capacity.

17

Individualdetermined capacities should not differ fromthe mean determined capacity by more than ± 1 partin 1 000.

B-2 PROCEDURE

8-2.1 As stated above, the capacity of the pipette canbe adjusted to suit the users' requirements. The overallcapacity of the butyrometer scale and the number ofpoints to be tested will determine the choice of capacity.It is recommended that at least three points on thebutyrorneters scale shouId be tested.

8-2.2 '1'0 illustrate the procedure recommended, it isassumed that a 0.25 ml pipette, complying with thetolerance specified, is available and it is required totest fourpointson the scaleofthe 8 percent butyrometer.

B-2.3 The butyrometer, previously cleaned and dried.is clamped vertically with the small bulb pointingdownwards. Mercury is run into the butyrometer, carebeing taken to avoid trapping air bubbles, until thetop of the rnercury meniscus is in a horizontal planepassing through the bottom edge of the 8 percentgraduation mark.

8-2.4 Before making the final adjustment to the mark,the butyrometer is gently tapped in order to obtain awell-formed meniscus. The pipette is then filled asdescribed above and the mercury delivered into thebutyrometer. The butyrometer is again tapped and theposition of the top of the mercury relative to the scaleis noted. Since 0.25 ml ofmercury has been transferredto the butyrometer, the scale reading should be 6.00percent and any deviation fonn this reading representthe error on the scale.

8-2.5 Successive 0.25 ml volumes arc transferred fromthe pipette to the butyrometer and the scale readingafter each delivery is noted.

N()TE - When adjusting or reading the mercury meniscus, astripof black paper is wrappedround the stem of the butyrometer,the bottom edge of the paper being horizontal and not morethan 1 mm above the meniscus, The meniscus. so shaded, isviewed against a white background. By adjusting the positionof the eye until the back and front bottom edges of the paperare coincident, errors due to parallax are avoided. Where linesarc carried completely round the tube these serve the santepurpose.

8-2.6 To avoid introducing small errors due to changesin the temperature of the mercury contained, it ispreferable not to handle the srnall bu Ib of thebutyrometer.

IS 1223 : 2001

T40

B

.,

--"---3

c

120

~---10 ------~

.These are important dimensions, othersare forguidance only.

All dimensions in millimetres.

FIG. IS AUTOMATIC MERCURY PIPETTE

18

•

110

IS 1223 : 2001

ANNEXC

(Clause 7.4)

ELASTICITY TEST

e-l Carry out six Gerber determinations according tothe method prescribed in IS 1224 (Part I) or IS 1224(Part 2).

e-I.I Remove and keep the butyrometer intact in astand for 48 h, so that the stopper is in contact withsulphuric acid of the strength specified in 3. I of IS)224 (Part I) or IS 1224 (Part 2).

NOTE -- This would correspond to a continuous contact time

for nearly 200 Gerber tests.

C-l.2 After this period, remove the stopper from thebutyrometer and wash it thoroughly in water.

C-I.3 Carry out six more tests with the stopper asprescribed in e-l.C-l.4 Stopper passes the Elasticity test if there is nophysical damage has been done to the rubber part ofthe stopper and there is no change in elasticity ofrubber.

ANNEX D

(Clauses 10.2 and 10.9.2)

DETERMINATION OF CAPA('ITY ()F PIPETTES

0-1 PROCEDURE

0-1.1 Thoroughly clean the pipette. Clamp it in avertical position with the jet downwards and fill withdistilled water up to a short distance above thegraduation mark, retaining the water in the pipette bypressing a finger on to the top of the suction tube.Wipe the outside of the delivery jet free from waterwith a piece of clean filter paper. Allow the water torun out slowly by reducing the pressure of the finger.As the descending water surface approaches thegraduation mark, increase the pressure of the fingerso as to bring the water surface to rest with the lowestpoint of the meniscus in horizontal plane containingthe top edge of the graduation mark. Remove the dropofwater then adhering to the jet by bringing the insideof a glass vessel, say a beaker, into contact with the jetand detaching the drop on the side of the vessel. Placea clean weighed glass beaker or other convenient vesselbeneath the pipette so that the tip ofthe jet ofthe pipetteis in contact with the inside ofthe vessel. Then removethe finger from the top ofthe pipette and allow deliveryof the water into the vessel. Allow the pipette to drain

19

for) 5 seconds after visible outflow has ceased, the jetremaining in contact with the inside of the receivingvessel, throughout this period. Remove the receivingvessel at the end of the draining time from contactwith the jet of the pipette. To determ inc the instant atwhich visible outflow cease, observe the motion ofthewater surface down the delivery tube of the pipetteand take the instant at which the meniscus comes torest slightly above the lower end of the jet at thebeginn ing of the 15 seconds drain ing period.

D-I.I.I Determine the mass of the water thusdelivered.

0-1.1.2 Carry out all the operations at roomtemperature. Observe the temperature of water andcalculate the volume of water delivered by the pipetteat 27C\C by applying appropriate corrections for thewater temperature.

N() fE .- The method of delivery descrihcd above leaves asmall quantity ofwater in the jet of the pipette and when usingthe pipette. no method of emptying. such as blow ing out, shouldbeused which expels liquid completely from the jet or increasethe natural rate of delIvery.

Bureau of Indian Standards

BIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 to promoteharmonious development of the activities of standardization, marking and quality certification of goodsand attending to connected matters in the country.

Copyright

BIS has the copyright of all its publications. No part of these publications may be reproduced in any formwithout the prior permission in writing of BIS. This does not preclude the free use, in the course ofimplementing 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 reviewedperiodically; a standard along with amendments is reaffirmed when such review indicates that no changes areneeded; if the review indicates that changes are needed, it is taken up for revision. Users of Indian Standardsshould ascertain that they are in possession of the latest amendments or edition by referring to the latest issue of'BIS Catalogue' and 'Standards: Monthly Additions'.

This Indian Standard has been developed from Dec: No. FAD 57 (591).

Amendments Issued Since Publication

Amend No. Date of Issue Text Affected

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