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 1885-53 (1980): Electrotechnical Vocabulary - Part LIII: Mica [ETD 1: Basic Electrotechnical Standards]

IS:lt38s(P8~tLIII)-lpp( SupmediEg 1: 11744957 )

Indian StandardELE~TROTECH~~~~ VOCABULARY

PART Llll tiCi

Electrotcchnical Standards Sectional Committee, ETDC 1Chairman R6#666nting

&SRI J. s. ZAVJRI Bharat Bijlee Ud, -bayMembws

SARI I-I. V. BADRIE~~~T~ Wireless Planning and Coor&mation Wing ( Ministryof Comanmications ). New Delhi

Siuu V. K. BATMsssw T. L. BHATIA

National Physical Laboratory f CSIR ), New l+hiIndian;ys a+ Telegraphs Departpent ( Mmistry

SHN J. M. N-Y ( Alternatr )olllmunlc8t~), * DeBI

smu v. s. ~mrmah

BRIO N. DAYALcbLK.v.KuDvA(Qtanurtr)

D~E~ToR(TBJ~) . central Electricity Author&y (Department of

DEPulY&(TED.)I(Altmrr)Power)-[ Ministry of Energy ), NC? Delhi

SHRI M. L. L~ONORE Power Cables sectional Committee, ETDC 59, IS1%~IuR.D.J*IN Con&&xa and Accassories for Overhead Lines

sau s. EL--4%Sect@@ colI@w, BTDC Bo, ISI

J@t-x$~:~~~ W Shopal

Pitox’ R. C. NAMYANAN

E g y.&AR”

Smu H: M. PAI

C%WZdN=XU&tUU m and Symbols Subcommittee,ElTDa 93 s;asr

Sxuu D. N. PURANDAREqmlmitp+BTDQ58*~s1 , ”

Ekotg~&W~~sIAccesso~, Sectional Committee,

Sis4u s. 0. RAMAcHANDRA Rotaa. Ma&wry Sectional Commlttce, El’DC 15.

SziRr v. L. SASTRY Electronics and Radar Developnrent Establishment

SHU K. V. BI.IAT ( &FlUlt6 )( Ministry of Defence ), Bangalore

DRS.M.SEPlDR H. V. K. UDUF%

Institution of Engineers ( @ia ), Ca’cuftaSeoonmd&Es;nd Batteries Sectmnal Committee,

9( Continusd on Pcrgs 2 )

@ Co@ight 1980INJ.%AN STAND- W4TlTU‘MON

Tbis publication is pro@ted undex the Zndka Compr&u&m in whole or in part by any means ewxpt3%

’ ht Act (XIV of 1957) andwritten permission of the

publishor aball be deemed to be an infrinpemslrt of dopyrigbt under the said Act.

( Continusdfronr &ye 1)

Mrmbars R+ns#mtingSHRI H. N. VENKOBHA RAO Central Electrochemical Research Institute ( CSIR ),

Karaikudi ;Smtr Y. MAHADE~A Irm (Alternuts)

SHRI M. P. wAt3H lndia&m;l;trical Manufacturers’ Association,

SHRt S. D. MEDHEKAR ( Altaate)SHRI S. P. SACHDEV,

Director ( Elec tech ) ( Ssmtmy )Director Gaueral, IS1 ( Es-o#cio Member)

Mica Sectional Committee, ETDC 9Chaimtan

SHRI S. N. PURI Geological Survey of India, CalcuttaMombcrs

SHRI S. P. BHADANI Cl&mm Horilram Pvt Ltd, P. 0. Jhumri-Tel&a,( Bihar )

SHRI QOPI KRISHNA BHADANI ( Altemak )SHRI BASUD~V BHARATIA Bihar Mica- Barters Association. Giridib

SHRI N. S. CHAKRAB~R~ ( Aftmate) _CHAIRMAN, BIHAR MICA SYND~CATR Gorernmant of BiharCONTROLLER Indian Bureau of Mines, Nagpur

SHRI M. MUKHERIEH ( Alternate)SHRI Y. N. DAVE Departmeut of Mines and Geology, Government of

SHRI R. S. SHARMA ( Altematc)Rajasthan, Jaipur

SHRI G. C. DESHru P. P. SAXENA ( Altcmatr )

Export Inspection Council of India, Calcutta

SHRI D. GUPTASHRI P. KOTA REDDY

Mica Trading Corporation of India Ltd, Paina.Madras Mica Association, Gudur ( Audhra P&ah)

SHRI C. V. KRISHNAIAH ( Altanats)SHRI SIUNKAR PRASAD Seth Pusalal Mansiughka Pvt Ltd, Bhilwara

MANSINOHKASHRI N. S. N. MURPHY Bharat Heavy Electricals Ltd. Hvderabad

SHRI M. V. D&AL ( Al&mm )_ _

SHR~ B. K. Mwrm~~ ( Altmuus )SHRI SUIIYA.&AW$H NATHANYSHRI R; L. hKh4iHIA

. ln personal capacity ( Mica Exporter, B&U )MM C. M. Rajgarhia, Giridih (Bihar )

SHnt-8. K, RAJOARHXA (Aikmolr)SHRI A. SY MASUNDARA REDDYsHRIs.a Y.$0

DRS. MUJD ,~.4i~). ,:~!%RI Krsro Ku %+A

f&l&r A. K%ibRy ( AliPkti #lq@mpics Pvt Ltd, Calcutta

SHRI BISHWAHT S&uyA Ml&g Association, Jhum&Telaiy&

SHttr IJrbmsH CHANDRAhRAWALA (Al&mate)

SHRI S. R. SENOUFTA Ranjam Mii Industries, CalcuttaStIRI u. s. VIiUfA Nab-1 Tast House, Calcutta

SHY P. C. PtUVHAH ( Ahnate )SHRI OM WADHWA f. V. Electronics Lttl, New DelhiSHRI S. P. SACiiDaV, Director General, IS1 (Ex+tio Mm&r)

Director ( Elec te& ) ( Secrrtarg )

2

hdian StandardELECTROTECHNlCAL VOCqBULARY

P A R T LIH IWICA

0 . F O R E W O R D0.1 This Indian Standard ( Part LX11 ) was adopted by the IndianStandards Institution on 4 July 1980, after the draft finalized by theElectrotechnical Standards Sectional Committee in consultation with theMica Sectional Committee had been approved by the ElectrotechnicalDivision Council.

’ 0.2 The definitions contained in this standard have been drawn up withthe object of striking a correct balance between absolute precision andsimplicity. The principal object of this ‘standard ( Part LIII ) is toprovide definitions which are su5ciently clear sb that each term is under-stood with the same meaning by all concerned. It may sometimes befelt that the definitions are not sufficiently precise, do not include allcases, do not take account of certain exceptions or are not identical withthose which may be found in other publications designed with otherobjects and for other readers. Such di!Ibrences are inevitable andshould be accepted in the interest of uniformity and clarity.

0.3 This standard (‘Part LIII ) supers&s 19 : 1174-1957..

0.4 Muscovite and phlogopite mica dlBer in composition, colour and afew other physical properties. While muscovite mica ( also known aspotash mica ) is a mineral of potassium alumino-silicate, phlogopitemica ( also known as magnesia or amber mica ) ‘consists of potassiummagnesium alumina-silicates. Colourwise, muscovite mica varies betweengreen and ruby and phlogopite mica ranges. from pale yellowish toblackish brown.

0.5 The quality of muscovite mica is judged by the degree of freedomfrom imperfections which are found in natural mica. These imperfectionsarise from various causes; some appear as structural defects, while othersappear as stain resulting from inclusions of various foreign materials;principal among them are the inclusions of air and mineral matter( see-3.11 ). Any system of grading and classification of muscovite micashould be based on a clear understanding of the terms which are used inmiea industry and trade to describe these imperfections.

+Dethitiom of mica tams.

3

IS t 188s ( Part LIII ),- 1980

0.6 Taking into consideration the views of producers, consumers andtechnologists, the Sectional Committee responsible for the preparation ofthis standard felt that it should be related to the trade practices followedin the country in this field. Furthermore, due weightage had to be givento the need for international co-ordination among standards prevailingin different countries of the world, and to include terms pertaining toboth the muscovite mica and phlogopite mica in this standard.

0.7 Requirements in respect of the minimum thickness of block micaappear to be different in different consuming countries. For this reason,in defining block mica, the minimum thickness has been stated to beeither 0’20 mm or 0’18 mm as agreed between the buyer and the seller(see 2.6). Producer countries are known‘to be prepared to supply blockmica to either of these limits.

, 0.8 The minimum number of splittings in a book should not be lessthan 8, and all such books shall contain sound splittings. A maximumtolerance of 10 percent of books, by mass, containing not less than 6splittings shall be permitted ( see 2.9 ).

0.9 While preparing this standard, assistance has been derived from thefollowing:

IS0 2185-1972 Muscovite mica blocks, thins and films - Visualclassification. International Organization for Standardization.

ASTM D 351-1971 Specification for natural muscovite block micaand thins based on visual quality. American Society for Testing andMaterials.

1. SCOPE

1.1 This sfandnrd ( Part LIlI ) covers detinitions of terms applicable tomuscovite and phlogopite mica.

2. TERMS REtATING TO GRADING

2.1 Crnde Mica -The crude crystals or books as extracted from themine. _, ,. , _2.2 C&Mug - The process of removing dirt and rock from crude mica.

2.3 Rifting -The process of splitting cobbed mica into sheets of suitablethickness.

2.4 Trimming or Dressing= The’ process of removidg major flaws fromrifted mica. Trimming may be accomplished with sickle or knife and themica is then named after the implement used, sickle-trimmed mica andknife-trimmed mica.

2.5 Sickle-‘Er~med Mica - Crude mica cobbed, rifted and trimmedwith a sickle to eliminate major flaws, and left with irregular outline andbevelled edge.

2.4 Blocks -Knife-trimmed mica of a speci&d minimum thickness,which may be, with a maximum tolerance of 5 percent ( by mass ).

Nom - As agreed betwem the bu cx and the reller, the thickness and ~~rre~pond-ing toieranco would be either of the allowing?

Thicknas Tolmanc4m m m m

020 -092048 - 0’03

2.7 Ths - Knif&trimmed mica in any specified thickness between1 0’05 mm and 0’18 mm.

2.8 Cemmerehl Forms of Mica - Mica known as blocks, thins, conden-ser films and spljttings.

2.9 Splittings- bminae split from blocks or thins, the thickness often of which taken together does not exceed 0.28 mm. Splittings may bepresented in two forms:

a) Book-Form Splittings - Splittings arranged and supplied inthe form of individual books, each book comprising splittingsobt8ined from the same piece of; block mica or thins. Book-form, ?#iW& cua;

LE”F”u, y ,c)urxtd wit4 fine mica powder. The

minimum number o s$ittmgs in a book should not be less than8, and aJl such boo@ ahoW:eontain only sound splittings. Amaximum tolerance of 10 percent of books by mass; containingnot less than 6 splittings, should be permitted.

b) Loose-Pack Splittings - Splittings of heterogeneous shape, notarranged in any regular order but packed loosely in bulk form.Loose-pack splittings may or may not be dusted.

2.10 Half-Trimmed Mica - Mica trimmed on two sides, with at leasttwo-thirds of the pieces trimmed on two adjacent sides, the balanceof the pieces trimmed on the two furrahel long sides, and with no cracksextending into the usable area by which the piece is graded. Theforegoing does not apply to sixes 6 and fi ( or 06 and 16 ) on which atleast one of any two trimmed sides must be free of cracks, and no cracksmay extend into the area by which the piece is graded. The mica shall‘be capable of permitting the cutting of rectangles of accepted size andquality with a weight loss not exceeding 60 percent of the tot81 inspectionsample,

5

2.11 ]PIIl-Trimmed Mica - Mica trimmed on all sides with ,a!l cr&~?,reeves, and cross-grains removed: ” ..:2.12 (Rife-Dressed Mica - ‘Crude mica dressed or trimmed with &if .‘orsickle-dressed or sickle-trimmed mica further refined with”i kni &bp:eliminate interior defects and also such defects as have been overlooicedby sickle-cutters.2.13 Unmanufactured Mica - The commercial form of. mica knotin asblocks, thins, films and splittings, as described.

2.14 Film - Full-trimmed mica of specified quality, split to any rangeof specified thickness between O-020 to 0’100 mm.

3. TERMS RELATJNG TO VISUAL CLASSIFICATION

3.1 ‘A’ -about 60”.

A series of rulings or striations intersecting at an angle of

3.2 Air Chain - A series of air inclusions or bubbles in the form of achain or streak.

3.3 Buckle - One or more large depression(s) and elevation(s).

3.4 Cracks - Irregular fractures within the crystal that may be naturalor may arise from blasting, rough handling, etc.

3.5 Cross-Gnios or Jatahl or Reeves - Tangled laminations giving im-perfect cleavage, which results in tears or breaks during splitting.

3.6 CrystaBograpbic Discoloaration - Appears as bands of lighter ordarker shades of the basic colour of the block of mica. Such bands aregenerally parallel to the crystallographic faces of the crystal from whichthe block was separated.

3.7 HairCrack or H&line Cracks - Minute, irregular cracks that arebarely noticeabk.until mica is split into films, resuEing in production oftorn films.

3.8 Hard. Mica - Mica tha ou&cn e,lght?y f&&i or distorted withthumb pressure, gunorally &Itid %how any tendincy to delaminate .Such .mica, in thick p&&a, -@ill gi%e an almost metallic sound whentapped or dropped on a hard surface( see @so 3.16).

3.9 Herring-Ronerr - Numerous rulings that intersect to form a series of‘V’,’ the legs markings anglea of 1W and joining at the apex to Rroduce aherringbone, horsetail, or feather structure.

3.10 Hole - A perforation, sometimes minute, through the lamiaae.

6 .I

3.11 hcltmiesl - Inter-cleavage penetration of a fore& material eitherof mineral origin or of gas (for example, air inch&s, mineral inclusion ).

NOTE 1 -Air inclusions apand grcyisb spots when

as rilvery bubbla wbcn viewed by reflected light,&tralmmittul fight.

NOTS 2 - The so-called ‘vegetable’ inclusions are of Pale yellow, brown green,or clay colour whm viewed by transmitted light.

~ Nona - Mine4 inclusions arc distinctly black, red, browu, or greed whenvicwcd by transmitt~ light.

3.12 Pinholes or Pinpits - Minute holes caused by crystals of hardminerals, such as garnet, quartz or beryl.

3.13 Ribbomed or Ruled Mica - Mica that breaks into narrow stripsbetween parallel fractures.

3.14 Ribs or Ridges - Crenulations in the form of steps.

3.15 Ripple - Multiple short waves.

3.16 soft Mica - Mica that, when slightly flexed or distorted withthumb pressure, generally shows a tendency to delaminate. Such mica,in thick pieces, generally gives a dull sound when tapped or dropped ona hard surface. (see also 3.8 ).

3.17 stains - Stains arise from foreign materials, resulting in a partialor total loss of transparency. ‘They may be% the form of specks orpatches of appreciable area - for example, slight stain, vegetable stain,day stain, black stain, red stain, black speckled, light dot or spot, black,red or ‘green dot or spot, black or red lines/bars inclusive of crosshatchings, etc.

Nom1 - The so-called ‘vegetable’ staias am of pale yellow, brown, green, orclay colour when viewad by traasmittcd I&l&

NOTES- Mineral stains are distinctly black, red, brown, or green when viewedby transmitted light.

Nom3 - No data are available to support the hpression that the ‘vegetable’stains arc organic in nature. Tests car&c&d indicah that they are finely dispersedparticles of. the varipus $m oxides. The .diffor+x bctwec~ tbcsc sta@ and theyacat mural stams 18 probably only 10 tbos co1Lodzltratwns, dcnslty, or type

3.18 Stones and Stone Holes - Small embedded crystals or holes result-ing from them.

$19 Tmgle Sheet - A piece of mica that splits well in places but tearsin others, producing a large percentage of partial films. Sometimes theterm is applied to intergrowth of mica crystals.

7

iS:18SS (l%rt LHI)-lg$O

3,20 ‘V*-Cuts or Figure Cuts — Edge cuts converging towardsthe centralarea of the mica piece.

3.21 Waves — A1tmnateelevations and depressionswhich may he classi-fied as slight, medium or heavy.

3.22 Wedge — A piece of mica that, on splitting, yields pieees thicker atone end than at the other.