vemx> 507.3

II-2 PREPARATIOtl FOR TEST

II-2.1 Preliaainarv steBS. Before inltieting amy testing:

a. Determine from the test plan vbich test procedures are required.

b. Determine from the test plan the tenperature-hiialdity operations and storage

requirements and corregponding tesperatis-hvdity cycleCs) from table 5C7.3-I.

c. The test chanber should be operated and its proper operation verified before the actual test is begin.

II-2.2 Pretest standard anbient checkout. All items require a pretest checkout at controlled ambient conditions (General Bequirements. 5.1b} to provide baseline data. For procedure I, this checkout should be conducted before step I. Conduct

the pretest checkout as follows:

Step 1. Insert the test item into the test chanber.

Step 2. Prepare the test item in its required operational configuration in

accordance with General Bequireusnts, 5.2.2

Step 3. Adjust the chamber to controlled ambient conditions (General Bequirements, 5.1b) and maintain for 24 hours.

Step 4. Conduct a conplete visual examination of the test item

Step 5. Docvnant the results.

Step 8. (kmduct an operational checkout in accordance with the epproved test

plan.

Step 7. Becord results for cospllanoe with General Beqxjiremants. 5.2.1.

II-3 РВО^Шта^. ТЪе following test procedures provide the necessary infomation concerning the test item in a warm-htsBld environment. Proceed to the first test procedure as specified in the test plan.

II-3.1 Procedure I - natural

Step 1. With the test it in the сЬ/иЛвр in its operational configuration, adjust the chaniber conditions to those given in table 507.3-1 for the tiaw 0000 of the specified cycle.

Step 2. Perform a 24-hour cycle with the time-teBperatxa-humidity vaiuas specified in he appropriate cycle or tha а^Ф^! cijrves cf figure 507.3-1.

St p 3. Perform an operational checkout of the teat Item at any convenient time in the 24-hour cycle during idiich test conditions are constant and at maximun tenperature and Я1 levels. Operational checks should be conducted

at least once svsty five cycles.

Step 4. Repeat steps 2 aiKl 3 for the пгшЬег of cycles indicated in table 507.3-II unless otherwiee directed by the requiz-ements documents.

Step 5. Adjust the chamber to controlled anbient conditions and maintain fro at least 34 hours.

Step C. Caa±x:b a cplste visial ехш!йпа%1оп cf the test item.

Step 7. Doctnmnt the results.

Step 8. Conduct an operational checkout of the test item in accordance itith the proved test plan.

Step 9. Doeimiint the results.

Step 10. С<яраге these data tlth the pretest data. II-3.2 Procedure il - induced

Step 1. Insert the test item into the chamber.

Step 2. If specified, open any sealed areas }other than heroatical ly sealed) of the test item.

Step 3. Adjust the chanber tenperature and relative hunidity to those shown

In the appropriate induoad Gategory of table B07.3-1 tap time 0000.

Step 4. Cycle the chamber air temperature and BH with time as shown in the appropriate cycle of table 507.3-1 (or in the approximated curves of figure 507.3-2) through the 24-hoiB cycle.

Step s. Bepeat step 4 for nur of ItMee indicated In table 507.3-II for the appropriate cvcle unless other guldatnce is provided by tbe test plen.

Stp 6. Adjust the chanber to controlled anbient conditions and maintain for 24 hoxs>s following stabilization of the test itenL

Step 7. Conduct a ccsplsta visual suseckout of the test item

Step 8. Docunant the results.

Step 9. Put the test item in its normal operating configuration. Step 10. Cond\x:t a conplete operational checkout of the test item.

Step 1. Prapere the test iten in accordancse with Оаяета! BequLremmts, 8u3.2. and perform the pretest standard asbient chedcoiit.

Step 2. Graduaily raise the internal (Camber tegperatw* to oCC (14 and ths relative hvssidity tc 95% l5X over a period cf tea hours.

Step 3. kbintain the conditions of step 2 for not less than six hours.

Step 4. Maintain BSX or greater relative hunidity and reduce the internal chaaiber temperature in eit hours to 30°C (вв* and 99% +5X relative humidity. . .

step 5, ifaintain Uie ЗООс IBbPT) end 95% +5T relative hydity for additional eight hours.

Step 6. Repeat steps 2,3.4, and 5 for a total of 10 cycles (not less than 240 hoxjrsi.

Step 7. Hear the end of the fifth td t > <les, diile still at SG9c tS&*W) and 05% relative hurddlty, operate the test item and obtain and record results in accerdanoe with Qeneral Bequlremants.

II-4 ШГОВМИТКЖ TO BE НВСХДРЕР

a. Tsst itss idsntifissticn (asnufacturer, serial srushsr, etc).

b. Previous test methods to tdileh the test item has been subjected.

c. Results of each perfommnce check (pre-, during, and post-test) and visual examination (and photograi, if applicable).

d. Length cf tisss required for each perforssncs dis. a. Procedure and test levels used.

f. Exposure durations.

g. Time versus tenperature and humidity.

ICTBOD 507.3

s-ie

step 11. DoouBmt the reeulta.

Step 12. Соцраге these data vnth the pstest date.

II-3.3 ProcMitM III - AStfpavated (Sea flSUM S07.3-31 .

a. Direct attack oi nif. fT>(yif Nonresistant materials are suscieptible to direct attack as the fungi break the material down etnd lise it as food. This results in deterioration affecting the physical properties of the material. Examples of nonresistant materials are:

(1) Natural materials. (Prcxiucts of natural origin are most s\iSceptible to this attack.)

(a) Cellulosic materials (e.g., wocxl, paper, natural fiber textiles,

and cordage).

(b) Animal- and vegetable-based adhesives.

(c) (9rease, oils, and many hydrocarbons.

(d) Leather.

METHOD 508.4 FUNOUS

sBcmam i

I-l РШРОвЕ...................... 508.4-1

1-2 EMVIKMBfEirrAL EFFECTS............... 508.4-1

aUIDELIHES FOR ХЖТЕВШКИХЗ TEST

FIPCEDORES AND TEST С(Ж>1Т1СЯВ.......... 508.4-2

1-4 SPECIAL O0MSI№RATIONS............... 508.4-4

1-5 BEFEESNCES ..................... 508.4-6

SECTION II

II-l APPARATUS..................... 508.4-7

II-2 PREPARATION FOR TEST................ 508.4-9

11-3 PROCEDURES..................... 508.4-10

II-4 INFQRMATKW TO BE HEOOREfiD............. 508.4-15

SECTION I

I-l PURPOSE. The purpose of the fungus chanber teat is to assess the extent to which the test itemvrlll support fungal growth or how the fxjngal growth may affect perfomance or \sie of the test item.

1-2 ENVIBMngNTAL iflTTJCIS. Fungal growth inpairs the functioning or use of equipment by duoiging its idiysical properties.

1-2.1 Detrimental -effects. The detrimental effects of fungal growth are siammrised as folic

SSTBOD 508.4

(2) Synthetic wateriala:

(a) PTC fopsEUlations (e.g.. those plasticiaed with fatty acid esteFS).

(b) Certain polyurethanes (e.g., polyester and some polyethers).

(c) Plastics №ich contain organic fillers of laminating materials.

(d) Faints and varnishes nich contain susceptible constituents.

b. Indirect attack on materials. Damge to fungus-reeistsoit materials results from indirect attack Aen:

(1) Fungal growth on surface deposits of dust, grease, perspiration.

and other contaminants ( ich find their way onto equipment during manufacture or

acciJESLilate during service) causes dafflage to the mderlying naterial, even though that STsterial may be resistant to direct attack.

(2) Metabolic waste products (i.e., organic acids) excreted by fungi cause corrosion of metals, etching of glass, or staining or degrading of plastics and other materials.

(3) The products of futngal growth or adjacent materials shich are susceptible to direct attack come in contact with the resistant nateriala.

1-2.2 Phvsical interference. Physical interference can occur as follows;

a. Electrical or electronic systems. Damage to electrical or electronic systems may result from either direct or indirect attack. Fungal growth can form undesirable electrical conducting paths across insulation materials or may adversely affect ths electrical characteristics of eritieally adjusted electronic circuita.

b. Optical, systems. Damage to optical systems results primarily from indirect attack. The fungal growth can adversely affect light transmission through the optical system, block delicate moving parts, and change nonwetting surfaces to wetting surfaces with resulting loss in perfomance.

1-2.3 Health and aesthetic factors. Fungal growth on equipment can cause physiological problems (e.g., allergies) or be so aesthetically xjnpleasant that the users will be reluctant to use the equipment.

1-3 OUIDELIMES FOR DETERMIMIMG TEST PBDCEDURES AMD TEST CCHOITIOMS

НОТЕ- The tailoring process as described in section 4 of this document should be vsed to determine the appropriate test and test variables.

a. Application. Since microbial deterioration is a zwctiOTi of twerature and ntmdity and is an inseparable condition oi hot-huaid tzpics and midlatitudes,

it sust be considered in the design of all standard, general-purpose aaterlel (refermce a). This method is used wtien an item is to be tested to determine if fisigal growth will occur and, if so, how it will affect the use of the test item.

b. Bestrictions. This test is designed to economically obtain data on tbe susceptibility of materiel. It should not be used for testing of basic mataPials sinoe varioxiS other test procedures, including soil burial, pure culture, Bdxed culture, and plate testing, are available.

c. Sequence. (See General Bequiresmnts, 5.1.4.) litis method should not be condxKted after a salt fog test (method 509.3) or a sand and diet test (method 510.3). A heavy concentration of salt тку affect the germinating fisigal growth, and sand and dust can provide nutrients, thus leading to a false indication of toe biosiseaptiblity of the teat itea.

d. Test variations. In addition to an optional operational test at the end of the fungus test, test variables include duration of test and test item configuration.

1-3.1 Test .objectives. The primary objectives of the ftngus test are to determinet a. If ftsigi will лго on thm test item (see 11-3,1.2a for the types of fungi). b. How rapidly fisigi will grow on the test item.

c. How any fisigal growui affects the test item.

d. To utat extent tha fungus will affect the mission cf the test item.

e. If the test item can be stored effectively in a field environment.

f. If the test item is safe for use following ftsigad growth.

g. If there are slnple reversal processes, e.g., wiping off ftstgal growth.

1-3.2 Caюioef related testeonditions. Once a determination has been Bade as to fdietber or not an operational requirement exists, the next decision oust concern test duMttion and test item configuration.

a. Test duration. Twenty-eight days is the adnimitt test period to al low for

fungal gersinatim, braakdoivi of carb mslseules, and degradation of naterial. Since indirect effects and .ysical interference are net likely tc occur in the relatively short time frame of the fungus test, extension of the exposin period to 84 days should be considered if a greater degree of certainty (less risk) is required In determining the existence or effect of fuigal growth.

iSTBOD 508.4

mL-STD-eiOE 14 JULY 19

b. TwtteBLConf i<vg >tion. ТЪ t *t itmu oonf iguration ie an iB>ortant factor. Evan though equipoMnt ia to be protected by a container, the container could leak and entrap moiature. Aa a miniaiuin, tha following teating configuratlona ahould be considered:

(1) In its norsal shipping/storage contairier or transit case.

(2) UMer realistic storage or use coTxlltlons.

(3) With restraints (such as with openings tbat are nonaally covered).

c. Additional Huldelinea. Bevlew the equlposnt aped float ions and

requlrensnts doctsisnts. Apply any additional guidelines necessary.

1-3.3 Choice of test fungi: Five species of test ftsigi are listed in II-3.1.2a. Ibese organlsns were selected becaiee of their ability to degrade B terlals, their

worldwide distribution, and their stability. They nust be xised in all method S08.4 testa.

a. Because the test item is not sterile before testing, other microorganisms % 111 be present on the surfaces. Mien the test item is inoculated with the five test fungi, both these and the other organisms will coapete for available nutrients. It ia not aurprialng to aee organisms other than the test fungi growing on the test

ites at the end of the test.

b. Additional species of fungi may be added to those required in this test method. However, if additional fisigi are used, their selection shall be based on prior knowledge of specific material deterioration. For exanple, Aureobasidiian pullulana can be enployed because of its kno n specificity for degrading paints.

1-4 SPECIAL ОСЯВТПВДАТТГЦВ

1-4.1 Failure analysis

a. Any fungi on tbe test item must be analyzed to determine if the growth is on

the test it№ material (s) or m contasinants.

b. Aiw fxsigal growth on the test item material (s), viwther fхчяа the inoculua or other sotD43es, nust be evaluated by qualified personnel for:

(1) Tbe extent of growth on the coaponentCs) supporting growth. Table 503.4-1 can be used as a guide for this evaltJation.

(2) Tbe innadiate effect that the growth has on the physical characteristics of the test item.

№ГЖО 506.4

(3) The long-range effect that the growth could have on the test item.

(4) The specific material(s) (nutrient(s)) supporting the growth.

G. Dlsturbanc-a cf any fungal growth asjst be kept to a minisum during the operational eout.

d. Hunan factors effects nust be evalviated.

1-4.2 MisceUaneous

a. This method is designed to provide optimal climatic conditions and all of the basic inorganic minerals needed for growth of the fuftgal species utsed in the test. The group of fungal species was chosen for its ability to attack a wide variety of materials connonly leed in the constrijction of military equipment. Optional species may be added to the inoculum if required (see 1-3.3).

b. This test must be jierfcmisd by trained perscr.nel at laboratories specially equipped for microbiological work.

hETHDD 508.4

c. The test tenperature and humidity cycle selected for this test involves a 5 C drop in tenperature to al low moist air to enter the test item (breathing effect) and the moisture to condense onto or in the internal cciipcnents. thus sinulatir an outdoor diurr.al cycle.

d. The presence of moisture is essential for spore germinations and growth. Qeneral ly, germination and growth will start wtien the relative hunidity of the anjbient air exceeds 70%. Development will become progressively more rapid as the humidity rises above this value, reaching a maxinum in the 90 to 100% relative humidity range.

e. The specified tenperature range, 24° to 31°C (75° to 88°F), is most conducive to the growth of the test fungi.

f. Control items specified in 11-3 are designed to:

(1) Verify the viability of the fungal spores ised in the inoculum,

(2) Establish the suitability of the chamber environment to support fungal

groMith.

1-4.3 Sumarv of teat infomation required. The followring inforraation is required in the test plan for ths adequate condvsct of the tests of section II:

a. Test item configuration.

b. Test duration.

e. (tional pre- arid post-test cperatior,al rsquiremsnts. d. Additional guidelines. 1-5 KKblslKKWCES

a. AB 70-38, Research. Develoiaisnt. Tsst ar-d Evaluation of ifeteriel far-Extreme Clinatic Conditions,

b. MIL-STD-210, Climatic Information to Detsrmine Design and Test Requirements for Military EguitMnent. 9 January 1987.

METHOD 508.4 FUSGMS SECTION II

II-l APPARATUS Il-l.i TMt yaeJMty

л, Tha required аррагаЪШ СОПЯ lets of chanbers or cabinets, together ith auxiliary instrtimentation capable of maintaining and monitoring the specific conditions of teaoperature and hvnidlty, that conply with Qeneral Requirements, 5.1.1 and 5.1.2.

b. The chssbsr and accsssories shall be constructed and arranged in such & ssTJier as to prevent conder.sation from drippir.g on the test item.

c. The chainber shall be vented to the atmosphere to prevent the buildup of pressure.

1 л a a. ч

a. Relative humidity shall be determined by enploying either solid-state sensors whose calibration is not affected water condensation or by an approved equivalent method such as fast-reacting wet-bulb/dry-bulb sensors. Lithivm chloride sensors are not reconmended because of their sensitivity to wter.

(1) When the wet-bulb control method is ted, the №t-bulb assenbly shall be cleaned and a new wick installed for each test.

(2) The air velocity across the wet bulb shall not be less than 4.6 meters per second (900 feet per minute).

(3) The wet- and dry-bulb sensors shall not be installed in the discharge side of aiu local fan or blower used to create the ieqiilrement of II-1.2a(2).

b. Provisions shall be made for controlling the flow of air throughout the internal test ciamber space so that the air velocity shall be between 0.5 and 2

meters per second (98 to 394 ft/min).

c. Free circulation of air around the test item shall be maintained, and the contact area of fixtures st4>porting the test item shall be kept to a minimsn. (See General Requirements, 5.2.2)