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ЫЕПКЮ 502.3

g. Clothing and special equipment used to set щ> or disasseoble the test item.

h. Test teaperatures.

i. Duration of each exposure.

j. appropriate anthropometric measuorements of perswutel perfcrsirig manipulation tesU.

k. Tenperature-time-versiJB data (test item and chamber).

1. Initial analysis of any failvs.



method 503.3 TQUPEBATURE shochc

PAGE

rim i

i-l fospcse ................. ..... 503.3-1

!-2 SVIB0m®IT . Snrars............... 503.3-1

1-3 (jDidelises for ceraacKim test

pwcedubes and test oohditicms.......... 503.3-3

1-4 SPECIAL CONSiraSATIONS............... 503.3-9

1-5 BEFEREMCES.................... . 503.3-9

звсткж ii

ii-1 крршвт..................... 503.3-10

ti-2 PREPARATION pot TEST................ 503.3-11

ii-3 PHOCEDURES ..................... 503.3-12

ii-4 INFORMATICW TO be RECORDED............. 503.3-12

SECTION I

I-l PURPOSE. Tenperature shock tests are conducted to determine if materiel can withstand sudden changes In the tenperat\s>e of the svn>roxjnding atmosphere without в]фег1епс1пв physical damage or deterioration in performance.

1-2 ENVIR£Biif*E*Prttff glrrCTS. As a result of exposure tc sxidden tesperatxse umges, operation of the test item may be affected either tenporarily or permanently. Sables of problems that could occur as a result of exposure to sudden changes in teaperature are:

a. Shattering of glass vials, and optical equipnsnt.

b. Bindir.g or slackening of eeving parts.

c. Separation of constituents.

d. Changes in electronic conponents.

s. Slsctronic or BSBchsnical fail%s*es due to rapid water or frost formation.

f. Cracking of solid pellets or grains in explosives.

g. Differential contraction or expansion of dissimilar materials.



This method may also be used as a screening test to reveal potential flans in eqiiipment exposed to less extreme conditiona.

b. Restrictions. This method is not intended for equipnent that will not experience sudden extreme tenperature changes beoauee of ita packaging, installed location, etc. This is not to be used to assess performance characteristics afer lengthy expoeure to extreme tenperatures. as are methods 501.3 and 502.3. Additionally, this method does not address the tenperature shock experienced by equipment vbich is exposed to warm air and solar-radiation heating and is then innersed in cold water, or the therna,! shock caused by rapid transient wanmp by engine conpreSSor bleed air.

c. Seoxience. (See General Requiremanta, 5.1.4) This test method should follow the high- and low-tenperature tests where test item response characteristics

and performance determinations have been obtained. Such information should be used for better defining the test conditions to be used for this procedure.

d. Test variations. This method has one procedire for which there are several variations in application (tenperature range). Before conducting the test, a determination nust be made as to which test conditions are appropriate. The test conditions that are used during the test are determined by:

h. Deformation or fracture of conponents.

i. Cracking of surface coatings. J. Leaking of sealed conpartments.

1-3 OUIDELIMES FOR DETEHMIMIMQ TEST PROCEDURES AMD TEST OQMDITICTIS

NOTE: The tailoring process as described in Section 4 of this docuoent should be used to determine the appropriate test and test variables.

a. Application. This method is applicable to equipment titiich may experience extreme rapid tenperature changes in its anticipated area or mode of deployment. These include:

(1) Ascent from a desert airfield (high tenperature) to high altitude (low tenperature) in ijnheated aircraft conpartments or stored externally. This includes equiiMoent such as aircraft external stores (electrical equipment pods, guided bonbs.

etc.), stores installed in bonb bays, and optical equipnent.

(2) Air delivery/airdrop from high altitude (low tenperature) to a desert environment (high tenperature).

(3) Transfer of (ground) equipnent to and from heated areas within a low-tenperature environment (includes air delivery to a cold environment).



(1) Tha expected exposure tenperatures.

(2) The test Items logistic configuration.

(3) Thm test items deplGjnssant configuration.

(4) The test Items extreme storage tenperatures.

(5) AAditional guidelines as appropriate. 1-3.1 Choice of test variations

a. Operational purpose of the test item. FW>m the requirements docisnents, determine the ftsictlon to be performed by the equlpnent and the deployment or deployment location < hich could result in exposiire to sudden changes in anbient tenperature.

b. Test objectives. The primary objectives of tbe tenperature shock test are to deterel.ne if:

(1) The test item can satisfy its performance requirenants after exposxire to sudden changes in tenperature of the surrounding atmosphere.

(2) Thm test item can be safely operated following exposure to the sudden changes in tenperatu of the surrounding atmosphere.

c. Selection of the test variations. Several exposure situations are addressed within this method: aircraft flight ехроаш>в, air delivery - desert, and ground transfer or air delivery - arctic. Based on the anticipated deployment, determine vtilch test variation is applicable. Thm moat extreme exposiire range should determine the test ccnditier.s, but test levels nay be extended to detect design flue.

(1) Aircraft flight exposure. This Is appropriate If the test item is to be exposed to desert or tropical gi>ound heat and, a few minutes later, exposed to the extreme low tenperatures associated with high altltvide.

(2) Air delivery - desert. This is aqpropriet-e for eqtsipment Miich is delivered over desert terrain from vnheated, high-altittjde aircraft.

(3) QroiSKl transfer or air delivery - arctic. This is intended to test equipmant for the effects of movement to and frooi heated storage, maintenance, or other enclosures or a heated cargo conpartment in cold regions.

(4) EnSineerins desKn. This is used to detect marginal design or workmenship practices.

1-3.2 Choice of related test conditions. After choosing the test exposure variation, select the test tenperatures, test durations, test item configuration, and any additional appropriate variables. Values other than those suggested may be used if realistic.



МЕТЮО 503.3

a. Teat tein[>eratupeg. The test temperatures are preferably selected from field data or from the requirements documents. If this information is not available, the test taiiperatwes can be deteFmined хгош the anticipated deployment alieation or KSDrld areas in vAich the test itsm ssill be deploysd. or frosi ths most sxtrsas nonoperating tenperature reqmrements.

(1) Deployment application (aircraft flight exposure). The thermal stresses that equipment will experimoe during expoeure to this operational environment are dependent ijpon the anbient conditions, flight conditions,

and performamce of the onboaod environmental control systems.

(a) The tenperature and hunidity at various altitudes can be found

in MIL-STD-210.

(b) Table 503.3-1 shotas tenperatures typical at ground level in hot climates. The teiuper-atures shown are based on fr-eqvieni of ocaurrenoe and correspond to a l-pseroent frequency of oecjrrence at or close to the . geographical boundary between the category of interest and the next-more-

severe category. The probability of occurrence increases as the distance from this line into the category area increases. Table вОЗ.З*-!! and figijre 4 (General Requirements) can be used to determine test tenperatures for the antlcipateu ueploynient locations.

(2) Air delivery/airdrop. The test conditicms for this exposure are based upon the conditions that will probably exist in the cargo conpartment of the aircraft and on the ground at the point of inpact. The lower tenperature extreme should assume an \jnheated, unpressurized aircraft cargo conpartment with the aircraft at an altitude of 8 kiloneters (26.200 ft). This is the limiting altitude for oia>go aircraft becaijse of oxygen-pressure requirements wtien the aircraft cargo conpartment is vsnpressiJD*ized iniediately before airdrop pperatlonfi. The tenperature at this altitude over a desert can be foxind in MIL-STD-210. The high tenperature surface extremes ahould be determined according to 1-3.2a, from tables 503.3-1 and 503.3-II, or from nethod 501.3.

(3) Ground t-ansfa-/ai- deli vary - arctic. The conditions developed for heated enclosures located in cold regions are 21°G (70°F) and 25 percent relative hunidity. These conditions iere selected to rotighly correspond

to normal heating practices in the Arctic and on aircraft. Selection of the outside anbient conditions should be based tpon the clinmtic categories or areas listed in table 503.3-III.



TABLE 503.3-1. Diurnal evcle of teaperature for

high-tenperature clinatic cateHories.

Hot-dry

Basic hot ;

AabiMit

Induced

Anbient

Indixl

Teqperature

Temperature

Tenperature

Tenperature

i Tine

°C

°F

Op !

i 0100

91 !

i 0200

! 35

! 32

91 i

: 0300

94 : 32

90 !

i 0400

- 88

88 ;

! 0500

92 ! 30

Ш

! 0600

91 ; 30

88 !

! 0700

93 :

! 0800

101 :

! 0900

107 J

; 1000

113 ;

! 1100

i

124 :

: 1200

i

134 :

i 1300

1400

: 1500

: 1600

! 1700

! 1800

134 !

1900

122 !

i 2000

Ill :

! 2100

1

101 i

! 2200

1 39

95 :

: 2300

. 37

! 2400

. 35

91 !

503.3-5



шь-зпьвкж

14 JULT 1080

Table 503.3-II. Hi<h teaperature <eo<raBhioal cliaatlc categories.

Category 1/

! Hot Dry (Al)

Location 2/

Cliaaitic Conditione

Operatimal Induced

°C (?F) J С ( F)

Basic Hot (A2)

Northern Afrlea, Middle East. Pakistan. India, soutlmestem №ited States and northern Maxico.

Qctending out rd from the hot-dry category of the United Statea, Maxico. Africa, Asia, and including Australia, southern Africa, Sovtth America, aoxithem Spain and aouthweat Aaia.

32-40

(00 - 130) 8 to 3X BH

30-43 ! (88 - 110) : 44 to 14X RH:

33-71 (01 - 180) 7 to IX RH

30-83 (88 - 145) 44 to 8X ]

1/ See table 503.3-1 for the diurnal tenperatis/hiaidity cycles of these clinaitic categories.

2/ See Qeneral Requirements, figure 4, for locations.

№THDD 503.3



TABLE 503.3-III. Low-tenж>erature geographical climate categorieg.

Clientic Coridlticsts

Category t Location

S Operational\

S -6° to -16* C I : (21° to -2°)I

-10° to -21*4; S (14° to -e°F) i

Ш1А Gold COO)

i (Coastal areas of : Ihetem Europe under ; prevai 1 ing -marltime ; influence, eoxttheaat : Austral la, lowlands of ; B8W Zealand.

Basic Cold (Cl)t Most of Ешюре.

) northern contigwus US

; southern Canada,

i High-latitude coasts,

t e.g.-, southern eoast

i of Maska

: High elevations in

! low latitudes

Cold (C2) i Horthem Canada,

: Alaska ( :cludir,g the i interior).

I Greenland (excluding the

I -oold pole).

I northern Scandinavia,

i northern aflia (Some areas) ,

I Tibet.

I Шф1 Elevations

(Horthem and Southern Haaispheres):

i Alps

I Hiaalayas

; Andas

Severe Oold (CSS): Interior of Ala ; TiScon (Canada) , : interior of the I northern Islands, i apewtland ice cap, ; northern Asia

-SlOp

! -21° to -31°C ! 1-6 to -24*)

S

! -37*> to -4e®G ?(-35< to -5lOc)

: :

-25 to -33®C { (-13® to -27Tf) J

-37<* to -4e°c I (-35** to -51**F) :

-51*0 (-e0°F)

3/ See General Bequirements, figure 4, for locations.



(4) Erntineeriiut design. The test conditions should reflect the extpene

anticipated Storase COTiditlons.

b. Test item tenperatures. The information in I-3.2a is intended

to describe the air tenperatures to wtiich equiixnent will be exposed during various types of operations. Determination of the actual eqxilpment tenperatures will be based on time of expected exposure artd type of exposure. Actual onboard aircraft equipment tenperatures can be calculated during a thermodynamic analysis as in method 520. estimated based ipon expected flight difatioPiS. or assvsssd to be in equilibrivm with the surrounding air conditions. Actual response tenperatxiree achieved vAien equipment is exposed to the climatic conditions of the various ground climatic categories could be obtained from the test results of high- and low-tenperature exposure (methods 501.3 , 502.3, and 505.3) for either the <4>erational or storage configuration. The latter assvsiption nust take into account the induced effects of solar radiation during storage and transit in various climates.

c. bctrenie bijihtenperature exposure. An item is likely to eiqperience the highest heating during storage in the sui in the Hot Dry and Basic Hot climates. Therefore, transitions from hot to cold will be conducted with the test item stabilized at its high-Storage tenperatis*e. Transitions from cold to hot will be conducted vsith the high-tenperature facility air tenperature at the maxinun storage tenperatwe of the acnropriate cycle. IsPEfsdiately fQllo>>>ing this гш1я*вг. the hi-tenperature facility %till be cycled through the appropriate diurnal cycle (table 503.3-1) from the beginning of the hour at vbich the maxinun air tenperatxire is experienced until the test item response tenperatxnre is reached. Other tests, such as electron screening, may require even more extreme tenperatures.

d. Duration of exposure. The objective of this test is to determine the effect of rapid tenperature changes on the test item. Therefore, the test item nust be exposed to the tenperatxjre extremes for a duration equal to either the actual operation (i.e., actual flight time) or to that required to achieve tenperature

stabilization.

e. Test item configuration. The configiiration of the test item strongly affects teat results. Therefore, the wtticipated cpnflgvration of the item dis*ing storage, shipment, or use should be used dxjring the test. As a mininun, the following configurations should be considered:

(1) In a shipping/storage container or transit

(2) Protected or unprotected.

(3) Deployed (realistically or with restraints).

(4) Modified with kits for special implications.

(5) Packaged for airdrop.

€ТКЮ 503.3



1-4 ШШ1

1-4.1 Failje analysis. The failure criteria ef General Bequiremurite, 5.2.7, apply.

1-4.2 TesV-Conditions. Tbe test conditions as presented in this procedure are intended to be in general agreamant with other extrenms described in this docunent. Ibe primary purpose in establishing these levels is to provide realistic conditions for the traverse between the two tenperature axtrasas. Thxjs, tha tasparaturas at *ilch the item is stabilized before transfer nust be the most realistic, or possibly Ше Bost extrMie, that would be encountered during the sp K2ific operation.

1-4.3 1ГШ1ГУ test information required. The following information is required in the test plan for adequate oondijct of tbe tests of section II:

a. Test itssk ccatf iguraticn.

b. Test tanperatxsre extxmes.

c. IXв^ation of езфоаиге at each tenperature.

d. Test it b response teaperature (f j>ea isSsthod 501.3).

e. Tbe high-tenperature cycle, the test item response tenperature, and the initial teaperature for tbe teaperature cycling.

f. Mditional guidelines.

a. AB 70-38. Beaearch. Development. Test and Evaluation of-lfcteriel for Extreme Clinatic Conditions, dated 1 August 1979.

b. nIL-STD-210. Clinatic Inforaation to Detenaine Dssign and Test its for Mllitarv Systems and Eguipnant. dated 9 January 1987.

c. Synopsis of Back<rouid ifcterlal for MIL-STD-210B. Climatic-Extremes

for Milityv Eauipamnt. Bedford, MA: Air Force Canbridge Research Laboratories, 24 JaniMry 1074. DTIC nudber AD-TSO-SOB.

d. НАТО STAMAG 2831, Climatic Environmental Conditions Affectinjt the Design of Materiel for use bv M.4T0 .forces Operating in a QpQxmd Bole.

f. Balatlve ff1<t*Y The relative humidity ШЮ diirlng portions of this test could be a factor in tha resistance of the test it-em tc tesperatts>e shodc. Equlpmtnt fith a bl Distue content could be affected by freezing of the moisture. In most cases, tbe BH say be tsicontrolled, but specific BH values may be required itfien RH It be taken into consideration.




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