. . Downloaded from https://www.everyspec.com . . MIL-STD-81OC a. If the interruption from the beginning with occurs early in the test, the teat should be restarted a new test item or a cleaned item (see 11.3.3.la). b. If the interruption occurs late in the test cycle, examine the item for evidence of fungal growth. If the test item is bioausceptible, there is no need for a retest. If there ‘iano evidence of fungal growth or if the interruption occurred early follow the guidance as shotm below. (1) Lowered temperature. A lowering of the test chamber temperature generally will retard fungus growth.
If there is no evidence of mycological deterioration and the relative humidity has been maintained as in 1.5.lb(3), re-establiah test conditions and continue the teat from the point that the temperature fell below the prescribed tolerances. (2) Elevated temperature. Elevated temperatures may have a drastic effect on fungus growth. Any rise in temperature above 31° C (88° F) for a period of 4 hours or more shall result in complete re-initiation of the test. Any more moderate risk in temperature without evidence of mycological deterioration, and maintaining of the relative humidity as in 1.5.lb(3), - re-aatablish test conditions and continue the teat as if no interruption had occurred.
(3) Lowered humidity. Any drop in humidity levels below 90 percent, for a period of “4hours or more shall result in complete re-initiation of the teat. If a more moderate drop in relative humidity occurs that doea not result in fungal deterioration, re-establish test conditions and continue the test as if no interruption had occurred. When re-initiating a teat although it is preferable’to uae a new teat item, the same test item may be used if cleaned as speciflad in 11.3. la. New COttOn control strius shall be placed in the test chamber and both the test item and controls wili be reinoculated with the test fungi. ! 1.5.3 ~a a. The fungus test is designed to biosusceptibility of materiel.
It materials since a variety of other economically obtain data on the should not b.eused for testing of basic test procedures, including soil burial, pure culture, mixed culture and plate testing are available. b. Method 508 is designed to provide optimal climatic conditions and all of the basic inorganic minerals needed for growth of the fungal species used in the test. The group Of fungal species was chosen for.Its ability to attack a wide variety of materials commonly used in construction of military equipment. c.
The test temperature and humidity cycle selected for this teat involves a 50 Celsius drop in temperature to allow moist air to enter the test item (breathing effect) and condense onto or in the Internal components,”thus representing a natUral environment diurnal cycle. d. The presence of moisture is essential for spore germination and subsequent growth. Generally, germination and growth will commence when the relative humidity of the ambient air exceeds 70 percent. Development will. become progressively more rapid as the humidity rises above this value, reaching a maximum in the 90-100 percent relative humidity range. METHOD 508.2 508.2-5 .). i