d. Unless othepwise specified, the test chamber tenperature and relative htmidity shall be recorded continuously.

e. Readout charts shall bs readable tc within lP.e**C (±l°7).

t. The desired hunidity shall be generated by using steam or mter having a resistivity of not less than 250.000 ohms/cm at 25* C.

(1) Live steam shall not be injected directly into the test chanber

WDrkir.g space bare it may have an adverse effect on the test it and siercbial activity.

(2) Rust or corrosive craitaminants shall not be inposed on the test item by the test facility.

g. Unless otherwise specified:

(1) All reagents shall conform to the specifications of the Ck>nmittee on Analytical Reagents of the American Chemical Society, vbere such specifications are available.

(2} References to water shall be vsider-stCGd to mean distilled ater or vunter of equal purity.

II-1.3 Test,intemption. Every case of an intem4>ted test shall be examined individually in accordance with Qeneral Requirements. 5.2.4. Any deviation from this policy shall be explained in the test report. The fungus test, uilike other

sjiviroimental tests. involves living orgwfilmnS. If the test is intersected, tbe fact that live organisms are involved Hbst be considered.

a. If the Interruption occurs during the first seven days of the test, the test should be restarted from the beginning with a new test item or a cleaned test item.

b. If the xntermtion eccur> late in the test cycle, exandne the test item for evidence of fuigal growth. If the test item is biosusceptlble. there is no need for a retest. If there is no evidence of funeal srowth. follow the guidance given below.

(1) LoMere<j temperature. A lowering of the teat chanber teaperature generally adll retard fvngal growth. If there ia no evidence of aycologieal

detsrioraticn and the relative huaidity has been isalntained, reestablish tha test conditions and continxie the test from the point *!ere the tesperatxire fell below the prescribed tolerances.

(2) Elevated tenperatxse. Elevated tenperatxires nay have a drastic effect

on fungal growth. A conplete reinitiation of the test is reqxilred if:

(a) The teirperatupe exceeds 40°С (104°F) . or

(b) The tenoperatxire exceeds 31°C (88°F) for four hoxjrs or more, or

(c) There is evidence of deteFlOFAtiOn of the fUTisal COlonieS oti the

control Strips, or

(d) The relative humidity drops below 50Й during the period of elevated tenperatures.

0ther%wise, reestablish test conditions and continue the test from the point of interrvjpiion.

(3) Lgmgred htjiudity. A conplete reinitiation of the test is required if:

(a) The relative humidity drops below 50%, or

(b) The relative humidity drops below 70% for four hours or more, or

(c) There is evidence of deterioration of the fisigal colonies on the

control strips.

Otherwise, reestablish test conditions and continue the test from the point of interruption.

c. Cleaning. Although it is preferable to use a new test item, the sans test item ney be toy cleaning required mt be conducted as least 72 hours before

reinitiation and must be in accordance with II-3.2.1. New cotton control strips shall be placed in the test chainber, and both the test item and the controls will be reinoculated with the test fvmgi.

II-2 FBEFARATION FOR TEST

II-2.1 Preliniinau?v steps. Before initiating any testing, determine from the test plan:

a. The test duration(s).

b. Thm test item configuratlon(s). e. Any other test variations.

II-2.2 Pretest checkout. All test items require a pretest checkout to provide baseline data. Conduct the checkout as follows:

ETдаD 508.4

МВТНС 508.4

Step 1. Prepare the test item in accordance with General Requirements. 5.2.2. and the required test item configuration as determined from the test plan.

Step 2. Conduct a остр lets visual sxaairticn of ths test itea with special attention to discolored areas, ioperfections. or the existence of any other conditions that could be cosfiducive to fungal growth.

Step 3. Docvsnent the results of step 2.

Step 4. Conduct an ox>eratlonal checkout In accordance with the approved test

р1ая if operation is specified by the reqiiiremsnts dccusant.

Step 5. Record results for compliance with General Requirements, 4.5.1.1. II-3 PTOCEDURES II-3.1 Test preparation

II-3.1.1 Preparation of mineral salts solution

a. Using clean apparatus, prepare the mineral salts solution to contain the followirig:

Potassiun dihydrogen ortbophosphate (XH2PO4) ........... 0.7g

Potassivm monohydrogen orthophosiiate (K2HPO4)........... 0.7g

Ihtgnesiun sulphate heptahydrate lUgSO-TH)........... 0.7g

MnoniuB nitrate (НЦНЭз)......... l=Og

Sodlun cdiloride (NaCl)....................... 0.005g

Ferrous sulfate heptahydrate (РезОТНгО) ............. 0.002g

Zinc sulfate beptahvate (SiSO m-0)............... Q.0Q2g

MenganouB sulfate aenohydrate (MiSOHsO)............. O.OOlg

Distilled water.......................... 1000 ml

b. Measiire the pH of the mineral salts solution. If it is not between 8.0 and 6.5, discard it and prepare a proper solution.

II-3.1.2 Preparation of mixed apore augpenaion

МСУГЕ - PRECAUTICAB: Altho\ b the exact etralna of fungi specified for this test are not normally considered to n>esent a serioiM hasard to huBoans, certain people may develop allergies or other reactions. Therefore, standing operating procedures (SOPs) for safety should be employed. Also, the tests should be condxjcted by personnel trained in microbiological techniques.

a. using aseptic techniques, prepare the spore siispension containing at least the followirig test fuigi:

TABI 508.4-11. Test furult.

Fungi

Puigte Sources Identification No.

ДТСл;-/

AsBerSillus niger Asperslllue flavus MPfrgJUvs versicolor

OjaatoBjiua Slobosua

(Si see

QM 380 QM 432 (Si 474 QM 459

woe 9642 ATCC 9643 ATOC 11730 ATCJC 11797 ATCC 6205

1/ US Department of Agriculture (ВЕА/РЮ Nortiiem Segional Sesearch Center

ASS Culture Cellaetisn

1815 Sortb Onivereity Street

Peoria, Illinois 00604

(The fuigi may be distributed in a lyophilized state or on agar slants.)

2/ American ppe (hiltupe (llection 12301 ParklasBi Drive Bocdcvllle, Ibryland 30852

b. Maintain pure cultias of these ftsigi separately on an appropriate mediun such as potato dextrose agar, but culture Chaetomium globosum on strips of filter paper overlaid on the sis>iace of mineral salts agar.

c. Pre; 3 slneral salts agar by dissolving IS.Qg of agar in a liter of the mineral salts solution described in II-3.1.1. NOTE: Do not keep the stock cultures for more than four months at 6° *A° (43° 7°F) after that time prepare subcultures and xsie them for the new stocks.

d. Verify the purity of fungus cultures before the test.

e. Incubate sxixrultures xsed for preparing new sto eult\s< s or the spore suspension at 30° ♦1.4°C (88** l.SF) for 14 to 21 days.

f. Prepare a spore suspension of each of the five fungi by pouring into one subculture of each fungus 10 ml of an aqueous solution containing O.Cg per liter of a nontoxic wetting agent such as sodium dioctyl sul f osuccinate or sodium lauryl

s-alfate.

g. Use a rounded glass rod to gently scrM the surface growth from the culture of the test organisms.

h. Pour the spore charge into a 125 nd capped Erlenmayer flask containing 45 ad of water and 50 to 75 solid glass beads. 5 вва in diameter.

1, Shake the flask vigorously to liberate the spores from the fruiting bodies and to break the spore cluqps.

J. Filter the dispersed fungal spore suspension into a flask though a б aa layer of glass wool eontainad in a glass funnel.

NOTE: This process should reoDve large nvoelial fragments and clups of agar.

k. Centrifuge the filtered spore suspension and discard the stpematant liquid.

1. Besuspend the residue in 50 al of mter arid centrlfta. ish tha spores obtained from each of the fuigi in this manner three times.

m. Dilute the final washed residue with mineral-salts solution in such a manner that the resultant 8i>ore suspension shall contain 1.000,000 1200.0(Ю spores per milliliter as determined with a counting chanber.

n. Bspsat this operation for each organism used in Uie test.

o. Perform a viability check for each organism in accordanoe with II-3.1.3a.

p. Blend equal voIubbs of the reaultant spore suspension to obtain tha final mixed spore axjspension.

NOTE: The spore suspension may be prepared fresh. If not freshly prepared, it

should be held at 6° *A°C (43° vjrF) for not more than seven days.

II-3.1.3 Control, items. Two types of control tests are required. Using the procedure of II-3.1.3a. verify the viability of the spore suspension and its preparation. By the procedure of II-3.1.3b, verify the suitability of the chaaber

envircnsBnt.

a. Viability of apore auspenaion

(1) Before preparing the cossposite spore siispension, inoculate sterile potato dextrose agu> plates with 0.2 to 0.3 ml of the spore suspension of each of the individual fungal specifies.

(2) Distribute the inoculisn over the entire surface of the plate.

(3) Incubate the inoculated potato dextrose agar plate at 24 ° to 31°C (75° to ee°F) for 7 to 10 days.

(4) After the incubation period, check the fungal growth.

ЖГШ.: Ths absence of copiovis growth of any of the test organisms over the entire surface in each container will invalidate the results of any tests using these sporsa.

b. Test, chantoer environment

(1) Prepare the following solution:

(a) 10.Og glycerol.

(b) 0,lg potassiisn dihydrogen orthophosphate (KHjPO).

(c) O.lg amnoniiim nitrate (ИННОз).

(d) 0.025g magnesium sulfate heptahydrate (MgSO THjO)> (a) O.05g yeast extract.

(f) Distilled water to a total Уо1шав of 100 ml.

(g) 0.{Ю5§ of a nontoxic wettirig agent such as sodiisa dioetyl sulfosuecinate or sodiim lavryi sulfate.

(h) HCl and NaOH to adjust the final solution pH to 5.3.

(2) Dip cotton stripe conforming to MIL-T-43566 into the above solution. After dippirig, rssowB the excess llqiiid from the strips and hang them to dry before plaein.g them In the chamber and inoculating.

(3) Within the chanber, place the stripe vertically close to and bracketing the test items so that the test strips and test items experience the same test environment. The length of the strips shall be at least the height of the test item.

(4) These strips are installed and inoculated along with the test item to insure that proper conditions are present in the incubation chamber to promote fungal growth.

MEL-STD-eiOE 14 JULY 1080

II-3.2 Taat.pertoriiance

II-3.2.1 Preparation for inciibation

a. Assure that the condition of the Item subjected to testing is similar to their condition as delivered by the manufacturer or customer for use, or as otherwise specified. Any cleaning of the test Item shall be acconplishad at least

72 hours before the beginning of the fvngis test.

b. Install the test item in the chanber or cabinet on suitable fixtures or suspended from hangers.

c. Hold the test item in the operating chanber (at 24° to 31°C (75° to вО°Г) and 05 *5X ВЯ) for at least four hours ImmBdiately before inoculation.

d. Inoculate the test item and the cotton fabric chanber control items with the mixed fungal spore suspension by spraying the suspension on the control items and on and into the test item(s) (if not permanently or hermetically sealed) in the form of a fine mist from an atomizer or nebulizer. Personnel with ajiproprlate knowledge of the test item should be available to aid in exposing its interior surfaces for Inoculation.

NOTE: In spraying the test and control items with conposite spore siispension, take care to cover all external and internal surfaces bich are exposed during ше or maintenance. If the surfaces are nonwetting, spray until drops begin to form on thmn.

e. Replace covers of the test items without tightening the fasteners (so that air can penetrate).

f. Start incubation ininedlately following the inoculation.

II-3.2.2 InCTibation of the test item

a. Incubate the test items isider a daily cycle of tenperature and hunidity conditions consisting of 20 hours at a relative humidity of 05 l5X and an air tenperature of 30° ±.1°C (86° *29F) followed by a 4-hoiB> period in wbich condition of 05X (♦5X, -OX) relative huaidity at 25° ♦.1°C (77° i2°F) are maintained for at least two ho\a>s. Up to a total of two hours of tbe 4-bou period will be used for the transitions of tenperature and relative hunidity. Tenperature and humidity conditions during tbe transition periods nust be as follows: tenperature 24° to 310 (75° to 88°F) and relative htsnldity above OOX.

b. Repeat the 24-hour daily cycle for the test duration.

МггаЕЮ 508.4

с. After seven days. Inspect the growth on the control cotton strips to verify that the environmental conditions in the chamber are suitable for growth. At this tlM, at least 90 percent of the part o£ the surface area cf each test strip located at the level cf the test item should be covered by fvaigi. !f it is net, repeat the entire test with the adjustments of the chairiber required to produce conditions suitable for growth. Leave the control strips in the chamber for the dxiration of the test.

d. If the cotton strips show satisfactory fungal growth after seven days, continue the test for the required period from the time of inoculation as specified in tha test plan. If there is a decrease in fungal growth cn the cotton strips at Ute end of the test as coqpared to the 7-day results, the test is invalid.

II-3.2.3 Inspection. At the end of the inctbation period, inspect the test item imnediately. If possible, inspect the item within the chancer. If the inspection is condxjcted outside of the chamber and is not aospletad in eight hour-s, return the test item tc the test chasJber or tc a similar humid environment for a minlnass of 12 hours. Accept for hermetically sealed equipment, open the equipment enclosure and examine both the interior and exterior of the test item. Record the results of the inspection, inclxjding information listed in II-4, as applicable.

WjTE.: Data shall be used for ooarison wnth the data obtained in 11-3.1.

II-3.3 QperatiQn/t a*e (to Ът oonducted onlv if required). If operation of the test item is required (e.g., electrical equipment), conduct the operation in the period as specified in II-3.2.3. Data shall be recorded for conparison with the baseline data obtained in II-3.1. Personnel with appropriate knowledge of the test item should be available to aid in exposing its interior surfaces for inspection and in making operation and use decisions.

II-4 IMFOHMATIOS TD Ш ШРотт.

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

b. Presence of evidence of fungal growth at the 7-day che and at the end of tbe test.

Location of fungi.

d. narrative description of growth, including colors, areas covered, growth patterns, density of growth, artd thickness of growth (and photographs, if necessary).

e. Test period.

f. Effect of fup.gl on performance or ise:

(1) Аз received from chamber.

(2) After-iee maintenance.

g. Test conditions.

h. Condition of test item at time of test.

i. All deviations from specified test conditions:

(1) Tenperature.

(2) Humidity.

(3) Tims.

(4) Air velocity.

(5) Other.

j. Miether ths test items 3a rive directly from the mamjfaetijBr,

k. Test item history (previous tests).

1. Physiological or aesthetic considerations.

m. Types of fvngi used.

n. Besults of performance checks:

(1) Pretest.

(2) Fost-test.

lETHOD 908.4

METHOD 500.3 SALT FOQ

PAOE

SECTICMT I

I-l mtfOSE...................... 508.3-1

1-2 ekvikMSSTTAL EFFECTS............... 509.3-1

1-3 от1ш.1!ш FOR шшшашт test

FBtXrEDURES AND TEST CONDITIONS.......... 509.3-2

1-4 SPECIAL CONSIDERATIONS ............... 509.3-4

1-5 HlflTiHJICES..................... 509.3-4

SEOTICSi II .

II-l APPARATUS ..................... 509.3-5

II-2 PREPARATKHI FOR TEST................ 509.3-8

II-3 PRXCDORES..................... 509.3-10

II-4 1НР0ВМАТ1Ш TO BE RECORDED............. 509.3-11

SECTION I

I-l PURPOSE. Salt fo* climatic chanibar teats are performed to determine the resistance of equipment to the effects of an aqueous salt atmostere.

1-2. ENYIHCWIgirrAL ЫУЬТДЛЫ. Rte effects of exposure of materiel to an environment tnere there is an aqueous salt atSDSphere can he divided into three broad categories: corrosion effects, electrical effects, and physical effects.

1-2.1 С9ГГ< 1<?Л effects

a. Corrosion due to electrochemioal reaction.

b. Accelerated stress corrosion.

c. Formation of acidic/alkaline solutions following salt ionization in water. 1-2.2 Electrical effects

a. Inpaiment of electrical equipment due to salt deposits.

b. Production of conductive coatings.

c. Corrosion of insulating materials and metals.