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I ndian St andardIS : 2175 I 1999( bdlimwd 1995 )

SPECIFICATIONFORHEAT SENSITIVEFIREDETECTORSFORUSEIN AUTOMATICFIREALARM SYSTEM( Second Rev i si on

First Reprint J ANUARY 1999UDC 614842435 : 654.92454

@I Copyri ght 1989BUREAU OF INDIAN STANDARDSMANAK BHAVAN, 9 BAHADLJ R SHAH ZAFAR MARC

NEW DELHI 110002

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IS : 2175 1988Indian Standard

SPECIFICATION FORHEAT SENSITIVE FIRE DETECTORS FORUSE IN AUTOMATIC FIRE ALARM SYSTEM( Second Revision )

0. FOREWORD0.1 This Indian Standard ( Second Revision )was adopted by the Bureau of Indian Standardson 17 November 1988, after the draft finalizedby the Fire Fighting Sectional Committee hadbeen approved by the Civil Engineering DivisionCouncil.0.2 roperty damage caused by a fire is directlyrelated to the (a) intensity of fire, and (b) dura-tion of fire. The intensity of,fire depends uponthe time available for its growth, type andgeometrical configuration of combustibles,ventilation, etc. The duration of fire dependsupon the quantity of combustible and the pointat which the extinction process starts.0.3 Life hazard is predominantly posed bysmoke and other toxic products of combustionwhich travel faster and farther than fire. Theamount of combustion products and speed oftheir travel is directly proportional to theintensity of fire.0.4 In order to ensure life safety and reduceproperty loss, there is a need to detect fires inan incipient stage which will provide a reason-able interval of time for inmates to escape to aplace of safety and which will give a reasonablechance to fire fighters to control and extinguishthe fire with minimum loss.0.5 Fires are detected by utilizing various physi-cal and chemical changes produced by it. One ofthe phenomena for detection of fire is heat. Theprobes which.detect the early growth of fire bysensing heat due to temperature rise in thevicinity are called heat sensitive fire detectors.Typical examples are bimetallic, fusible alloy,pneumatic, etc.0.6 The aim of standardization of any device isto ensure that the quality of material is goodand that the equipment performs its task underthe conditions it may be subjected to during itsuse. It is, therefore, necessary to prepare anIndian Standard specification on heat sensitivefire detectors to enable the users to choose astandard device and also to help the indigenousmanufacturers to manufacture standard product.0.7 Heat sensitive detectors can be point ( spot)

line type detectors will be added later on. Thisstandard covering point type detectors was firstpublished in 1962 and revised in 1977. Thesecond revision has been prepared so as to bringthe requirements in line with the other inter-national standards and update the contents inthe light of developments made during the past11 years in this field. The principal modificationsmadea>

b)c)d)

e)

are:Rate of temperature rise type beingreplaced by rate of temperature rise-cum-fixed type detector;Covering both resettable and non-reset-table type detectors;Making provision for detachability;Keeping the temperature rating to caterto the requirements of normal buildingambient temperature and further dividingthe range in three grades in order to havethe maximum sensitivity;Including requirements and test methodsin respect of low/high temperature, voltagevariation, humidity; and

f) Including an accelerated ageing test fordetectors having fusible alloy link.0.8 This standard caters to the requirements ofroom ( ceiling ) ambient temperature not exceed-ing 45C which covers the majority of buildingsituations and for covering higher limit, aseparate Indian Standard is being formulated.The details of installation and maintenance ofdetectors are covered in IS : 2189-1988*.0.9 For the purpose of deciding whether aparticular requirement of this standard iscomplied with, the final value, observed orcalculated, expressing the result of a test oranalysis, shall be rounded off in accordancewith IS : 2-1960t. The number of significantplaces retained in the rounded off value shouldbe the same as that of the specified value in thisstandard. .

*Code of practice for selection, installation andmaintenance of automatic fire detection and alarmsystem ( second revision ).

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I S : 2175 - 19881. SCOPE1.1 This standard covers the general require-ments, test methods and performance require-ments for heat sensitive ( point ) detectors foruse in automatic fire alarm system.2. TERMINOLOGY2.0 For the purpose of this standard, thefollowing definitions shall apply.2.1 Control and Indicating Equipments - Unit(s)containing the controls, relays, switches andassociated circuits necessary to:

a) provide power,b) receive signals from alarm indicating( activation devices ) and transmit .themto the fire alarm devices and control forautomatic fire protection equipment, andc) electrically supervise the system circuitry.2.2 Detachable Detector - A detector designedto be easily removed from its normal operatingposition for maintenance and servicingpurposes.

2.3 Fixed Temperature Heat Sensitive Detector-A detector designed to operate when thetemperature of detector exceeds a pre-determin-ed value. \2.4 Line Detector - A linear form of detectorin which the detection process may take placeanywhere along its length.2.5 Non-Detachable Detector - A detector notdesigned to be easily removed from its normaloperating position for maintenance and servicingpurposes.2.6 Non-Resettable ( Non-Restorable ) Detector- A detector which after response requires therenewal of component or components to restoreit to its normal state of readiness to detect.2.7 Point (Spot) Type Detector - A detectorin which the sensing element is essentially of acompact area.2.8 Rate of Temperature Rise-cum-FixedTemperature Heat Sensitive Detector - Adetector designed to operate within a giventime:

a) when the rate of temperature rise at thedetector exceeds a pre-determined valueregardless of the actual temperature, andwhen the temperature at the detectorexceeds a pre-determined value.b)

2.9 Resettable ( Restorable) Detector - Adetector which after response and on cessationof the conditions that caused the response, maybe restored from its alarm state to its normalstate of readiness to detect withouf the renewalof any components.3. TYPES AND GRADES3.1 Heat sensitive detectors (both resettableand non-resettable ) covered in this standard are

>f the following types:a) Fixed temperature detector, andb) Rate of temperature rise-cum-fixed tem-perature detector.

3.1.1 C,ach of the above detectors are sub-divided into three grades based on the response:ime (see 5.2 ) as Grades 1, 2 and 3.1. GENERAL REQUlREMENTS4.1 The detector shall be,provided with meansfor mounting (on ceiling/wall) securely andindependent of any support from the attachedwiring. The heat sensitive element(s) shall notbe closer than 15 mm of the detector.4.2 Plastic, if used, shall not start softening,deforming or melting at a temperature lowerthan 95C.5. PERFORMANCE TEST AND CRITERIAFOR CONFORMITY5.1 A sample of required number of detectors(see Tables 1 and 2) of each design sele-cted randomly from production of not lessthan 200 detectors, shall be used for testing andshall be numbered. The test ( one or more )shall be carried out in the order given in testschedule by the methods mentioned in Tables 1and 2 and shall conform to the require-ments given in 5.2 to 5.9. The detectors shallpass all the tests. All the tests are type testswhich cover the production up to 10 000numbers.5.2 Directional Dependence and Response Time- Detector number mentioned in Table 1 or 2(as applicable ) shall be tested for these proper-ties according to the method given in Appen-dix A and shall conform to the response timerequirements for the three grades as given inTable 3 and in 5.2.1 (as applicable) in allorientations.

5.2.1 In case of rate of temperature rise-cum-fixed temperature type detectors, the followingrequirement shall also apply additionally.5.2.1.1 At rates of rise of air temperature

less than lC/min, the detector when testedaccording to the method given in Appendix A,shall be required to operate at an air tempera-ture of not less than 58C!, and for Grades 1, 2and 3 at not more than 65, 73 and 81C, respec-tively.5.3 Vibration - The detectors (see Table 1 or 2as applicable for numbering and rate of tem-perature rise ) shall be tested in the mannerdescribed in Appendix B and shall comply withits requirements.5.4 Corrosion - The detectors ( see Table 1 or 2as applicable for numbering and rate of tem-perature rise) shall be tested in the mannerdescribed in Appendix C. They shall be deemedto comply with the test if:

a) For Four Days Corrosion - The responsetime of each detector remains within the

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TEST PROCEDURE-_--A______~Clause Test5.2, A-2 Directional dependence5.2, A-3 Time of response

5.2, A-3 Response before test

5.35.4

VibrationCorrosion, 4 daysCorrosion, 16 daysCorrosion, Salt sprayShock.5w

5.6 Low temperature5.7 High temperature5.8 Supply voltage variation5.95.105.11

Insulation resistanceHumidityAgeing(applicable to fusiblelink type only )Response after test-3

TABLE 1 TESTING SCHEME FOR RESETTABLE DETECTORS( CIauses 5.1, 5.2, 5.3.5.4, 5.5. 5.6, 5.7, 5.8, 5.9, 5.10, 5.11, A-3.1. B-l.1 andD-1.1 )

DETECTORNUMBER RATE OFRISE T/MIN ) REMARKSI ___-h---- ----- fl_____- _-_____---111

1

1111

2

2

3 4 5

3 543 4

4 5

3 54

6 7 8 9 31 3 5 10 20 30 o-2Xx x x X Xx x x X X X

7 9 X6 8 10 X

o*o*

8 orientationsTwo tests at each rate : onewith most favourable orien-tation, other with leastfavourable orientation.With least favourableorientation

7 8 9 106

222

2

X

X X

X

7 8 9 10 X6 8 10

Tests at both rates at upperand lower limits of supplyvoltageMeasurement of resistanceonlyWith least favourableorientation

*Only for detectors subject to testing under 5.2.1 and 5.2.2.

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TEST PROCEDURE---------_~Clause Test

5.2, A-2 Directional dependence5.2, A-3 Time of response

5.3 Vibration5.4 Corrosion, 4 days

Corrosion, 16 daysCorrosion, Salt spray

5.5 ShockP 5.6 Low temperature

5.7 High temperature5.8 Supply voltage variation5.9 Insulation resistance5.10 Humidity5.11 Ageing ( applicable tofusible link detectors only )A-3 Response after test

TABLE 2 TESTING SCHEME FOR NON-RESETTABLE DETECTORS ti. .N( Ekch detector or element for one of the test only )(Cjauscs 5.1, 5-2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 5.10, 5.11, A-3.1, B-1.1 andD-1.1 )ELEMENT OR DETECTORSNLWWR RATE OF RISE ( CMIN )~_~_-~~~*~~~~~~-~1 to 8

1 to 89 to 2223 to 36

37 to 3839 to 4041 to 42

3843 to 4445 to 46

4748 to 51

525354

37, 39. 41.43, 453 8,40, 42,44,46

1 3

x xx x

5 10 20 30

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IS: 2175 1988

TABLE 3 ACCEPTANCE LIMITS FOR RESPONSE TIME( Cfartse 5.2 )

RATEOF RISE OFAIR TEMPERATUREDC/min

(1)135

102030

LOWER LIMIT OF UPPER LIMIT OF RESPONSF!Trw FORRESPONSE TIME FOR ,-____----------- A--_________~ALL RESPONSE GRADES Rccponse Grade 1 Response Grade 2 Response Grade 3c-_-*-__~ r--*___~ c--_h---~~~_~*~_--~min min min(2) (3) (4) (gs) ;k; (7s (8) ( 9,

30 0 37 20 45 40 54 008 13 12 40 1.5 40 18 4004 09 7 44 9 40 11 36

30 4 02 5 10 6 1822.5 2 11 2 55 3 3715 1 34 2 8 2 42

b)

limits of its grade with an additionaltolerance off 15 percent or 10 whicheveris greater.For Si xt een Days Corrosion - ( Sulphurdioxide and salt spray )1) Each detector gives an immediate con-tinuous fault signat on connection toits C & I equipment, or2) Each detector gives an alarm signal intime which does not exceed the upperlimits of response grade 3.

5.5 Shock - The detector (see Table 1 and 2,as applicable for number and rate of tempera-ture rise ) shall be tested in the manner describedin Appendix D. They shall be deemed tocomply with the test if:a>

b)no alarm is given when they are subjectedto the specified shock; andany change in response time of the detec-tors after the test when compared withthe response time obtained before the testdoes not exceed 15 percent or 10 s, which-ever is greater.

5.6 Low Temperature - Response time ofdetectors (see Table 1 or 2, as applicable fornumbering) shall be put .inside a suitablechamber/tunnel/enclosure and connected to itscontrol and-indicating equipment. Air tempera-ture in the chamber shall then be reduced to aminimum of 0 i 1C at a rate not exceedinglC/min. The detector shall be kept in thecondition of minimum temperature for 1 h toallow its temperature to stabilize. After 1 hstabilization, the detector shall be taken out andkept at a temperature of 27 f 3C for 5 to 6 hand then response times measured (see Appen-dix A ), one at 3C/min rate of temperature riseand the other at 20C/min rate of temperaturerise using least favourable orientation. Detec-tors shall be deemed to comply with this test if:a) no alarm is initiated during the test, andb) any change in response time of thedetectors measured after the test whencompared with the response time obtained

5.7 High Temperature - The detector (seeTable I or 2, as applicable for numbering/rate oftemperature rise) shall be mounted in thetunnel in its normal operating condition withits normal fastenings. Keeping the detectorenergized and disconnected from control andindicating equipment, temperature of air fiowin the tunnel shall be raised to 50C at a ratenot exceeding lC/min. The temperature atthis level shall be maintained for I h. Thedetector shall then be energized and the responsetime shall be measured (see Appendix A ) atSC/min rate of temperature rise using the leastfavourable orientation. The detector shallrespond within a timenot exceeding 11 min and36 s for Grade 3, 9 min and 40 s for Grade 2,and 7 min and 44 s for Grade 1.5.8 Supply Voltage Variation - The detector( see Table 1 or 2, as applicable for numbering/rate of temperature rise > shall be tested andresponse times measured as described inAppendix E. They shall be deemed to complywith this test if, as a result of supply variation,when compared with the response time obtainedbefore and after the test does not exceed 15percent or 10 s, whichever is greater and shallnot give false alarm during the test.5.9 Insulation Resistance - The detector (seeTable 1 or 2, as applicable) shall be mountedin its normal operating condition with itsnormal area fastening on a metal plate of atleast 2 mm thickness and having surface area atleast 5 times the mounting surface of the detec-tor. With the plate shorted to ground terminalof the voltage source, voltage shall be appliedbetween the plate and the terminals of thedetector which . are inter-connected. In 5 s,voltage shall be applied to a maximum of 500%10 volts DC. The maximum voltage shall remainapplied for one minute. Insulation resistanceshall then be determined. Thereafter, it shallbe subjected to a temperature of 43 f 2C andrelative humidity of 90 L- 3 percent for 10 days.After conditioning, the detector shall be keptat room condition for one hour. The insulationresistance shall be measured again. The detec-tor shall be deemed to comply with the test ifthe resistance in first measurement before the

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IS : 2175 - 19881 MQ, and the detector shall not give a falsealarm during the test.5.10 Humidity -The detector (see Table 1 or2, as applicable ) shall be kept inside a suitablehumidity climatic chamber and connected to itscontrol and indicating equipment. Followingclimatic conditions shall be created inside thetest chambers:

Temperature : 30 f_ 2CRH 80 f 5 percentDuration of : 7 daysexposure

The detector shall be transferred to tunnelwithin 1 hour of removal from the chamber andits response time measured according to Appen-dix A. The time measured after the exposureand before shall not differ by a factor greaterthan 16 and the detector shall not give falsealarm during the test.5.11 Ageing ( Applicable to Fusible Alloy LinkType ) - The detector (see Table 1 or 2, as appli-cable ) shall be placed in a suitable temperatureoven and exposed for a period of 90 days to anambient air temperature which is 15C belowthe rated operating temperature of the detectorbut not less than 50C. Following the exposure,the detector shall be allowed to cool for not lessthan 5 hours. After cooling, the detector opera-ting temperature shall be ascertained accordingto Appendix A. The detector shall operatewithin a temperature range T & (0035 T +062 )C.

NOTE - TC is rated operating temperature.6. INFORMATION6.1 Sufficient information shall be given withthe detectors to facilitate their correct applica-tion. Such information shall include broaddetails of general and technical features of the

detector, correct monitoring position, referenceto owners manual, operation of test feature ( ifprovided ), maintenance instructions, requiredelectrical interface with the control and indicat-ing equipment which may take the form eitherof the values of current, voltage, etc, and theirallowable tolerances or a restriction of thedetector to be used only in conjunction withspecified control and indicating equipment, etc.7. MARKING7.1 Each detector shall & legibly and indeliblymarked with the following:

a)b)c)d)

Manufacturers name or trade-mark;Type and description of detector andnumber;Year of manufacture:Grading of detector which shall be clearlyindicated either by the colours as men-tioned below, or by other suitable means;1) Grade 1 : green2) Grade 2 : yellow3) Grade 3 : red; and

e) Whether provided with fusible link.7.2 Each detector may also be marked with theStandard Mark.

NOTE.- The use of the Standard Mnrk is governedby the provisions of the Bureau of Indian StandardsAct 1986 and the Rules and Regulations made there-under. The Standard Mark on products covered byan Indian Standard conveys the assurance that theyhave been produced to comply with the requirementsof that standard under a well defined system ofinspection, testing and quality control which isdevised and supervised by BIS and operated by theproducer. Standard marked products are also conti-nuously checked by BE for conformity to thatstandard as a further safeguard. Details of condi-tions under which a lice&e for the use of theStandard Mark may be granted to manufacturers orproducers may be obtained from the Bureau ofIndian Standards.

APPENDIX A( Clauses 5.2, 5.2. 1.1, 5.6, 5.7, 5.10, 5.11 and Tables 1 and2 )

METHOD OF TEST FOR TIME OF RESPONSE AND DIRECTIONALDEPENDENCEA-l. APPARATUSA-1.1 The response time and directionaldependence shall be measured in a wind tunnelspecified in Fig. 6 of IS : 9972-1981*. The airvelocity in the tunnel shall be 08 & 01 m/s andthe air temperature shall be 28C.A-1.2 The detector shall be mounted in itsnormal operating position on a board formingpart of the ceiling of the working section of thetunnel so that it is symmetrically disposed with

thermocouple (copper-constantan wire notexceeding 025 mm in diameter, junction con- +sisting of a half twist with tightly tinned joint ).The temperature measuring device shall beapproximate, at the same distance from theceiling of the wind tunnel as the sensitive ele-ment of the detector and approximately 230 mmfrom the sensitive element against the flow of airin a horizontal direction. Before the test, thetemperature of the air stream and the detectorshall stabilized at 28C. The temperature con-

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fS : 2175 1988that the temperature can be raised from 52C ata rate not exceeding OTC/min to a temperatureof 83C.A-2. DETERMINATION OF DIRECTIONALDEPENDENCEA-2.1 The detector(s) shall be connected to itscontrol and indicating equipment and tested inan air stream having a constant mass flow,equivalent to a velocity of 08 f 01 m/s at28C and with a uniform rate of rise of airtemperature of lOC/min. Eight such testsshall be made, the detector being rotated about avertical axis by 45 between successive tests sothat the tests are made with eight differentorientations.A-2.2 The least favourable and most favourableorientations giving the greatest and the leasttime delays, respectively, between the initiationof the temperature rise and the operation of thedetector shall be recorded.A-3. TIME OF RESPONSE MEASUREMENTA-3.1 The detectors, the response times of

which are to be measured as mentioned inTables 1 and 2, shall be connected to the indicat-ing equipment and shall be tested in an airstream having a constant mass flow equivalentto a velocity of 08 & 01 m/s at 28C andhaving uniform rates of rise of air temperature1, 3, 5, IO, 20 and 3OC/min ( as applicable ).The scheme of tests for various detectors isgiven in Tables 1 and 2. The time intervalbdween the initiation of temperature rise andthe operation of detector shall be recorded toan accuracy of 05 s and shall be designated asthe time of response.A-4. FIXED TEMPERATURE OPERATIONA-4.1 TWO detectors shall be tested as in A-3with a rate of rise of air temperature notexceeding lC/min until the air temperaturereaches 50C and thereafter with a rate of riseof air temperature not exceeding 02C/min.One of the detectors shall be in less favourableand the other in most favourable orientation.The air temperature at the operation of thedetectors shall be recorded.

APPENDIX B( Clause 5.3 and Tables 1 and 2 )

VIBRATION TESTEl. PROCEDURE of any component shall be noted. If resonanceB-l.1 The detector (see Table 1 or 2, as appli- occurs, the detector shall be vibrated at thecable for numbering/rate of temperature rise ), resonant frequency for a period of one hour.connected to its indicating equipment, shall be If no resonance occurs, the detector shall bemounted in its correct operating position and vibrated at 50 c/s for one hour.response time (see Appendix A ) shall be noted B-1.3 No fault or alarm warningand then the detector shall be put on a vibration shall betable. The test shall then be subjected to a indicated and no mechanical defect ( includingvertical vibration of amplitude 01 mm for a the breakage/displacement of sensitivity seal, ifperiod of 5 minutes at each of the following provided ) shall be visible during or after thefrequencies: tests as in B-l.1 and B-1.2. The time of responseof two detectors shall be determined after the10, 15, 20, 25, 30, 35, 40, 45, and 50 c/s. test. The change in response, before and afterthe test shall notB-l.2 The operation of the detector or resonance exceedwhichever is greater. 15 percent or 10 s,

C-l. PROCEDUREC-l.1 At least 15 cm._ ._ _

APPENDIX C( Clause 5.4 and Tabl es 1 and 2 )

CORROSION TESTC-l.2 The detector ( see Table 1 or 2 as.of connection wires/cablesprescribed by the manufacturer shall bc con-nected to each detector or socket. When

specific types of wires/cables arc not prescribedfor connection, a 138 mm diameter ( or nearestequivalent > single copper wire, u:ltinned, shallbe used for connection Icads in this test. Thelowest point of the dctcctor shall be between25 and 50 mm above the liquid surface. Aguard shall be provided to prevent drops of

applicable for numbering ) shall be subjectedto a corrosion atmosphere of sulphur dioxidesaturated with water vapour and maintained attemperature of 45 rt 3C. The apparatus shallconsist of a 5 litre glass beaker fitted with acover, an electric heater, and a thermostat whichcan be set at 45 f 3C and copper tubing forflow of cool water round the beaker.

The thermostat shall be placed 140 mm abovethe bottom of the beaker. A hole is to be prov-

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fS : 2175 1988by placing in beaker, a solution containing 20 gof sodium thiosulphate ( Na,Sz01.5Hz0 > in500 ml of water. The detector shall then besuspended in beaker and 10 ml of acid consist-ing of 156 ml of normal sulphuric acid ( H2SOa )per litre of aqueous solution shall be addedtwice daily. During the test, the temperaturenear the detector shall be maintained at 45 f3C by the heater and the thermostat and waterflow in cooling coil shall be so regulated that thetemperature at the outlet does not exceed 30C.Where a test is intended to last for more than8 days, the detector shall be removed after 8days and the beaker emptied and cleared. .4further 20 g of sodium thiosulphate in 500 mlof water shall be put in the beaker, the detectorreplaced and the corrosive atmosphere producedand maintained as before for a period of 8-daysagain.

C-1.2.1 The first pair of detectors shall bemounted in the beaker and exposed to corrosiveatmosphere for a period of four days. Sixteendays exposure shall be given to the third detec-tor. After prescribed exposures, the detectorsshall be removed and allowed to dry for seven

days, in normal room environment withoutdisturbing the connections and the responsetime of detectors shall be measured as inAppendix A.C-l.3 Salt Droplet Test - This test shall beconducted on the fourth detector. The detectorshall be suspended with its lower edge 5 to 7Scm above the surface of water in a large dishand the whole shall be enclosed by a box-likecover. Once daily for a total period of 16 daysthe detector shall be removed, sprayed over itswhole surface by a spray of sea water of thefollowing composition and replaced under thiscover;

Sodium chloride? g/l 23Sodium sulphate, gll 89Magnesium chloride, g/1 98Calcium chloride, g/l 12

The temperature throughout the test shall bemaintained at 27 f 2C. After 16 days, thedetector shall be removed and allowed todry. Itshall then be connected to its normal indicatingequipment using the corroded lead and the res-ponsc time shall be measured as in Appendix A.

APPENDIX D( Clause 5.5 )SHOCK TESTD-l. PROCEDURE b) At the midpoint on the vertical side.

D-l.1 The response time of the detector ( see D-l.2 A metal block of 35 kg mass shall beTable 1 or 2, as applicable for numbering/rateof temperature rise for test ) shall be determin- dropped on to the midpoint of the 10 x 5 cmed. timber from a height of 30 cm above the topA detector incorporating electrical contacts horizontal surface of the timber. The detectorshall be mounted on a piece of 10 X 5 cmhardwood resting on edge on solid supports shall be connected in circuit corresponding toits normal operation during the test and shallspaced 1 m apart. The test shall be made withthe detector in the following two positions: not operate as a result of shock.a) At the midpoint on the horizontal under- D-l.3 After the test, the time of response ofthe detectors shall be determined ( see Appen-side, and dix A )I

APPENDIX E( Clause 5.8 )

E-l. PROCEDURESUPPLY VOLTAGE

El.1 When upper and lower limits of supplyvoltage are prescribed, detector(s) shall be testedat both the limits. At upper limit, two testsshall be carried out and similarly two tests shallbe conducted at the lower limit. When onenominal value of supply voltage is prescribed,two tests shall be carried out wifh voltage tocontrol and indicating equipment reduced as85 percent of nominal value ( to be treated tolower limit ) and further two tests with voltage

VARIATION TESTincreased to 110 percent of the nominal valueand the response time measured ( see AppendixA ). In each pair of tests, one test shall consistof the measurement of response time with arate of rise of 3C/min and the other with arate of rise of 20C/min. The response timesshall be recorded. For resettable detectors, thesame detector shall be used for all the tests ofE-1.1. For non-resettable detectors, a separatedetector or detector element shall be used foreach of the tests of E-1.1.

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Bureau of Indian StandardsBIS is a statutory institution established under the Bureau 01 Indiun Standards Act, 1986 to promoteharmonious development of the activities of standardization, marking and quality certification of goods andattending to connected matters in the country.CopyrightBIS 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 (Publication), BIS.Review of Indian StandardsAmendments 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 issueof BIS Handbook and Standards Monthly Additions.This Indian Standard has been developed from Dot: No.

Amendments Issued Since Pul~licstionAmend No. Date of Issue Text Affected

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