In a shipping/stcrsgs .container or transit case. (2) Protected or unprotected (taidar eanoiy. enclosed, etc.)

(3) In Its noml operating configuration (realistic or with restraints. Bijch as with openings that are noraaily cowered).

(4) Itodified tdth kits for special applications.

e. Hisniditv. Low relative bunldity (ВШ aay oooasionally have a aignifleant effect on soaa aaterlal during hlgh-tewratts teating. In auch instancea, oanslderatlan auat Ъе given to oontrellix BH as indicated

in tables 5G1.3-X and 5C1.3-ZI. >tbisnidsa. relative hieddlty (SSi eentrol during high tenperature tests is not

Cnqponents of a test itea that are kno n or suspected to be sensitive to the effects of high teaperatures and чЛмтт fadlin-e will affect the overall perforwnnoe of the test iten are referred to as critical itea

c-csponents. These ssspanents should be Idantlfled and thoroughly evaltmtod before this test to elisd!fs<..t(ssting SKpssuras t!at would not raalistiGally ba ansKsitarad by the test item during its life <ягс1е.

g. Adkiitional jHuidelines. Bevlew the equlpaant specifications and requirwants doctaaents. ikpply any additlenal guidelinas nacassaiy.

1-4.1 Failxs analysis. Tbe failure of a teat itea to meet the requireaants of the equipaant specifioetiona aust be enalysad-oarafully* and related inforaation auat be considered, auch aai

a. Besults ef nondestructive esoodnations (if any) of aateriel following the storage test may be emduefaad at the

b. Degradation or changes in operating eharacteriatica al lowed at the high extreme teBperatu>es.

c. Kscessity for special kits or special opsrating procedures f&r high teieratuf expeeure.

d. Evidence of iaproper lubrication and assurence that the Ixiiricents specified for the environmental condition were uaed.

1-4.2 Storage ffiodes. ibe studies conducted an stored materiel indicate that military equipment ia atored in a variety of modes. These modea range froa thoae that provide the greateet protection, such as controlled tesaperatijre-hidity warehouses, to those that are the most severe in terms of high-tenperatis stress, such as in open Ливр storage. KEraOD S01.3

1-5. Б

a. AR 70-38, Bsgeatrch. Develowner.t. Test and Evaluation, of Jfeteriel for Extreme Clinatic Conditions. 1 August 1979.

b. MIL-STD-210, Climatic Information to Determine Design and Jest Requirements For Military Systems and EouinmBnts. 9 January 1987.

c. Synopsis of Background Material for MIL-STD-210B. Climatic Extremes for Military EouiPBant. Bedford, MA: Air Force CaB!m idge Research Laboratories, 24 Januax 1974. OTIC number AD-780-50e.

d. UK Ordnance Board Proceeding 4189. 13 September 1977 (Draft STAIMG 2895).

e. KATO STASAQ 2831. Climtie Bfivirofmental Conditions Affectiru; the Design of Material for Use by МДТО Forces Operating in a (3round Role.

1-4.3 Sunroarv, of teat information required. The fol lowing information is required in the test plan for the adequate conduct of the tests of section II:

a. Test procedure.

b. Critical conponents, if applicable.

c. Location of tenperature sensors.

d. Test tenperature(s) or tenperature cycle and how the tenperatures were derived.

e. Test duration.

f. Test item conf Iguratlon.

g. Bslative humidity control requirsraents (if necessary).

h. Additional gviidelines.

KEraOD 501.3 HIGH ШРЕНСПЯВ SBCTIOM II

Il-i AFPflRpTuS II-l.l Teat facility

a. The x>equiped apparatua conaista of a chazriber or cabinet together with aiDciliary inatruaentation capable of aad.ntaining and continuoualy monitoring the required conditione of high tenperature (and huaidity, i Mre required)

throvicut an envelope of air s-arro-uTiding the test iteB{s). (See (Seneral Requiremanta, 5.1.1)

b. Air velocity in the vicinity of the teat item ahall not exceed 1.7 m/a (325 ft/min) unlesa Justified by the test item platform environmnnt to prevent unrealistic heat transfer in the test item.

c. Continuous recordings of ehaisber and test item teaperature msesuressante ahall be taken if required.

II-1.2 Coqroly

a. Twperature. (bless otherwise specif led in the tMt plwi. if any actisn . other than test itass operation (such as cpanirg the chasbar door) results in

a significant change of the test lt n teineratts<e teore than 20 СЗ.*Ю) or chaaijer air teaperature, the test item mill be restabilized at the required tenperat\jre before the test continues. If the operational check is not conpleted within 15 minutes, reestablish test item tenperature/BH conditions before oontxnuing.

b. Unless otherwise specified, tbe rate of twiperatwe change shall not exceed

3°C {e°F) per minute.

II-1.3 Test interr\s)tion. (See General Requirements, 5.2.4) a. TfctderteSt interruption

(1) (feline. If a cyclic high-tenperature test is being oondix;ted when an unscheduled interruption occurs that сашев the test conditions to fall out of allowable tolerances toward standard anbient tenperatxjrea, the test Bust be reinstated at the end of the last sucoesafully conpleted cycle.

(2) Steady-State. If a steady-state (noncyclic) test is being conducted and an unscheduled intewntion occurs that caxsea the test conditiona t-o fall out of allowable tolerancea toward standard anbient conditione. the teat item shall be

ИЕГЖЮ 501.3

pcetsbilized at the required test tenperature and the test continued from the point niiere test conditions юге left. Duration of initial and final test periods shall be recorded.

b. overtest interrtption. any interription in a clic or steacQf-state test that results in iSisre extreme ехровгаг-е of the test item than required Ъ^ the equipasnt specifications should be followed by a conplete physical Inspection and an operational check ( re possible) befoi>e continuation of testing. This is especially true where a safety problem could exist, such as with munitions. If a problem is discovered, the preferable course of action is to terminate the test and reinitiate testing with a new test item. If this is not done and a test item failure occurs during the remainder of the test, the test results could be considered invalid because of the overtest Gor.ditior.s. If no problem has been encctntered, reestablish pre-interruption conditions asid continue from the point tttere the test tolerances were exceeded.

II-2 PREPARATIOW FOR TEST.

11-2.1 Freliminarv steps. Sefore starting the test, deterraina from the test plan:

a. t!i6h test procedures ere required,

b. TtM high-tenperature operation and storage requirements and acconpanying tenperatts>e cycles and durations.

c. If relative hijnudity la to be controlled.

d. The looatlon of tenperature sensors.

e. The test items test configuration.

li-U.2 Pretest standard anbient, oheokout. All items require a pretest standard

asbient chackc-ut tc provide baseliris data. Conduct the checkout as fellows:

Step 1. Install tenperature sensors in, on. or around the test item as reqiiired by the test plan.

Step 2. Insert the test item into the chamber and stabilize the test item at controlled anbient craditions (General naquireewnts, 5.ib).

Step 3. Condijct a conplete visial exasunation of the test item wiUt special attention to stress areas, such as comers of molded cases.

Step 4. Document the results.

Step 5. Prepare the test item in accordance with General Requirements, 4.5.2, and

required test item configuration.

Stsp 6. CcTxiuct an operational checkout in accordance with the approved test

plan.

Step 7. Record the results for conpliance with General Baquirements. 5.2.1.

Step 8. If tbe test item operates satisfactorily, proceed to II-3. If not, resolve the prcble and restart at Step 1 above.

II-3 PROCEDUBES. Tbm following test procedures alone, or in conbination. provide the batsis for collecting the necessary information concerning the teat item in a high-tenperatisre environment. Proceed to the firat teat procedure aa determined by the teat plan.

II-3.1 Procedurea % - Storage

Step 1. Install the reqxiired tenperatxire sensors on. in, ai>d around the test item and chanber.

Step 2. Place the test item in its storage configuration.

Step 3. Adjvet the chanber environment to tbe initial test conditions as specified in the test plan.

Step 4. Ebcpose the test item to the teaperature (and huaidity, if applicable)

conditions of the storage cycle for at least aeven cles (a total of 188 hOiSw) or as specified in tha test plan. If applicable, sssnitcr the taspereture of the critical item conponents and docunent.

Step 5. At the conpletion of the last cycle, adjust the chanber air tenperatxs

to controlled anbient conditions and maintain until tenperature stabilization of the test item has been achieved.

Stsp e. Conduct a eeaplete visual and operati ml Aeout of te test item and record the results.

11-3.2 Procedure II - Operation

Step 1. Place the test item in the chanber in its operational configuration.

Step 2. From the test plan, determine the operational teaperatuf extreme(8), wbether constant or cyclic, and litether the tenperatxa>e(s) was:

a. Specified by the requirements docunants: Proceed to Step т for conatant teoperature шщюяшё or Step 12 for eyeling езфобита.

b. Derived from field measurements: Proceed to step 7 for constant tenperature exposure or Step 12 for cycling exposure.

VETHDD 501.3

c. Cyclic апЛ derived from 1-3.2: Proceed to Step 12.

d. Constant and not provided or determined eleewnere: Perform Steps 3

Uirou№ @.

Step 3. With the test item placed in the chanber in it operational configuration, inetal 1 the tenperature sensore necessary to measure the tenperature throuehout the test item, insuring that the critical conponents or areas of concern are included.

St 4. Adjust the chainber air conditions to the initial tenperature (and hunidity, if applicable) levels of the prescribed operational cycle.

Step 5. Expose the test item to the tenperature (and hunidity, if applicable) levels specified for the operational cycle for at least three cjrales, or as necessary to obtain repeated test item response (.2®C). A maxlnun of seven cycles is suggested if repeated response is dizzicult to obtain.

Step e. From the expostM data, determine the maxlnun critical-conponent tenperature or reonse tenperature of the test item. This will be the operational tenperature for Step 7.

Step 7. constant tenperature exposure, wath the teat item in the chanber in the operational configuration, adjust the diasber air teqMrature to the

operational tenperature and, if required, adjit Uie hufiidlty to the appropriate level of the cvcl: Maintain the chanber in a steady-state condition \sitil teoperatim stabilization of the test item has been achieved ((General Bequirements, 5.1.3).

Step 8. Conduct as conplete a visual examination of the test item as possible acr,siderir4 cheaber access limitations.

Step 0. Document the results.

Step 10. Operate Um test item until tenperature stabilization of tbe test item has been aahleved. Conduct an operational checkout of the test item in accordance with the approved test plan and document the results.

Step 11. Proceed to Step 15.

Step 12. (Vcling tenperature exposure. With the test item in the chanber in its operational configuration, adjust the chanber air tenperature (and humidi, if iplicable) tc the initial conditicrji of the operational cycle appropriate for the test item deployment.

Step 13. Expose the test item to at least three cycles or the nunber of cycles necessary to assure repeated test item response. Conduct as conplete a visual examination of the test item as possible considering chanber access limitations. Docunent the results.

№THOD 501.3

501.3-17

1/ The nsxiiasi response period aay not coincide with the saxisua tenperature carcle conditions because of thermal lag of the test item.

501.3

Step 14. Operate the test item dijring the mexinun reeponee period of tbe

exposure cycle. I/ Repeat isttil a ecaspleta operational secut of t! test item has been accoroliHhed In aecordmoe dth th* annroved test р1ш1 and ьЬл resulte have been docunented.

step 15. with the test item not operating, adjust Uie <ЯиаЬег air tenperatiee

to eantrcllad asblant CKSnditlons and maintain vmtll tenrature stabl 1 Isatlsn sf the test item has been achieved.

Step 10. Conduct a conplete visual examination and an operational checkout in accordance with the approved teat plan and docunant the raaulta.

Step 17. Conpare these data with the pretest data. II-4, ligPlMftTTOM TO BE mpomm

a. Test item identification (manufacturer, serial nudaer. etc.).

b. Previous tests to <iich the test item has been subjected.

Besults of eaoh рег'вячш ehaejt Mid viayBLl ewaninatim (and ЫюЪо>ав1ш. if wplieable) and ooapariaon with the failure criteria:

(1) Pretest. (3) Poat-test.

c. Record of chanber tenperaturea (and humidity if applicable) veraua time conditions.

d. Record of the teat item tenperatis>e-verevis-tiBM data for the dis tlon of the

test,

e. Initial failure analyaia.

hethod 502,3

METHOD 502.3 LOW te3)PERATURE

sscrriCK I

I-l resworn......................b02.3-1

1-2 EHVUKmCOTAL effects............... 502.3-1

1-3 aOIISLINES FOB DETEBMININa TEST

PROCEDURES AND TEST CONDITIONS .......... 502.3-2

1-4 SraCIAL оомзхитюш...............502.5-7

1-Э eiVlLtlBJIILiEO.....................ifVA.O~0

CTI f TT

II-l APPARATUS ..................... 502.3-9

II-2 PBEPARATIOH FOR TEST................ 502.3-10

11-3 PROCEDURES.....................502.3-11

11-4 1ШаВШПт то be ШООВаШ............. 502.3-13

SECTION I

I-l PURPOSE. Low-b4P patupe chanber teste are performed to determine if materiel can be stored, nanipulated, and operated mder pertinent low-teaqperature conditions without experiencing physical damage or deterioration in per z ormence.

1-2 стпгтяпммготАЬ la.yMris. Lew t №erati *es have adverse effects on alsost all basic materiel. As a result, еафоеиге of test items to low tenperatures may either tenporarily or permanently inpalr the operation of the test item by changing the idtysical properties of the material (s) conposing it. Therefore, low-tenperature tests nust be considered whenever the test item will be exposed to teeratwb below standard aoiwit. ExSIvb Of SSoS problenS that cOuld

occur as the result of axposusto cold are:

a. Hardening and enbrittlenent of materials.

b. Binding of parts fmn differential contraction of dissimilar materials and the different rates of expansion of different parts in response to tenperature

transients.

c. Loss of lufarioation and lubricant flow due to increased viscosity.

d. Changes in electronic cooponents (resistors, capacitors, etc.).

e. Cbangas In perfopnance of tpansformeps and lectponecbanical conponents.

f. Stiffening of shock oouits.

g. Cracking of 9xploBiv9 solid pellets or grains, such as авпоШип nitrate.

h. Cracking and crazing, eBi>rittlement, change in inpact strength, and reduced

strength.

f. Static fatigue of restrained glass, j. Condensation and freezing of Mater.

k. Decrease in dexterity, hearing, and vision cf personnel wearing pmotective clothing.

1. Change of burning rates.

1-3 ошра,1№5 for mmaamm test pbdcedures amp test cohditioms

НОТЕ: The tailoring process as described in section 4 cf this dccussnt should be issd to determine the appropriate tests and test variables.

a. Application. This method is used wiien the test item is likely to be deployed in a low-tenperature environment during its life cycle and the effects of low tenperature

have not been determined during other tests (such as the tenperature-altitude test).

b. Restrictions. This method is not intended for testing e<iuipa nt to be installed in and operated in aircraft, since stxdi equipnent would usually be tested according to method 520.

c. SeauBnee. (See Qmmr&i Requirements. 5.1.4) Because this test (except for the physical manipulation procedure) is less likely to permanently damage the

test item, it is normally scheduled вш>1у in e test sequanee. This test say significantly alter the performance of seals during the low-pressure testing of

500.2

d. Test variations. This method is conposed of three low-tenperatia subtests: Pixtcedures i (Storage), ii (Operation), and iii (Manipulation). Before the tests are

conduBted, a oice of one or more test procedures ssst be sade.

(1) The choice of test procedure(s) depends on the likelihood of the test item being:

(a) Operated 1/ at low teqperatures.

1/ Operation is the excitation of the test item with a miniaua of contact by personnel. It does not include handling (manipulation).

lIlEraDD 502.3

(1) The test item can nmet the perfomance specifications after storage or during operation in a cold environsnnt.

(2) The test item can be operated safely duririg or fcl Icwlr Icw-teaper-ature sxpesta a.

(3) The handling (nanipulation) required to make the test item operational can be conducted *ithout affecting its functional perfomance.

Based on this inzoraaation and the ривгрожт of the test item, detersiirie what test data, are necessary to ascertain to viiat extent the test item will satisfy its low-tenperatiM requirements.

.

c. ;Sylf94on Pf %itfJef9% propfyresW. Three test procedures are included within nathod S02.3: storage, operation, and nanipulation Based on the test data requirements, determine which test procedure, eoaabinatlon, or sequence of procedures is jplioable. In most cases, all three procedures should be applied.

(1) Procedure I-Stora<e. Procedure I is appro iate if the test item is likely tobe stored at low tenperatures dvsing its service life. Procedxs>e I is ,used. Miien it is necessatfy to determine how 1 o r-tenperature storage affects the test itenTs safety or perfomance. .....

lETHOD 502.3

502.3-3

(b) Stoi At low t Bpepattn!>M.

(c) Manipulated at low t qp ratupaa.

<2) Tha tMt ccmditiona that ам UMd dicing tha test ara dctaraainad Ъу:

(a) Tins expected tesaperatts at Uie deployaeBnt location.

(b) The eMpected duration at the deployeant looatlon.

(c) The test iten conf lgug*ation.

1-3.1 gfeyye pt pgQyftftipes?

a. Operational nupooae of the teat item. Pron the requirenente docmnnte. deteraaine the tuictione to he performed by the equipment in a low-tenperature environment and any liaaiting conditions, such as storage.

b. Test objectives. The primary objectives of the low-teaperature test are to dataraina if: