4.1 Test Facility
- a. For immersion tests, in addition to a chamber or cabinet capable of conditioning the test item to the required temperature, use a water container that can achieve a covering depth of 1 m (or other required depth) of water over the uppermost point of the test item and maintain the test item at that depth. To represent greater depths, it may be necessary to apply air pressure to the surface of the water.
- b. For fording tests, use a facility equipped with a tie-down capability to prevent buoyant test items from floating.
- c. A water soluble dye such as fluorescein may be added to the water to aid in locating water leaks.
4.2 Controls
Before each test, verify the critical parameters. Ensure the immersion test pull-down/hold-down device(s) are functioning properly and that there are no safety problems.
4.3 Test Interruption
Test interruptions can result from two or more situations, one being from failure or malfunction of test chambers or associated test laboratory equipment. The second type of test interruption results from failure or malfunction of the test item itself during operational checks.
4.3.1 Interruption Due To Chamber Malfunction
- a. General. See Part One, paragraph 5.11 of this Standard.
- b. Specific to this Method.
- (1) Undertest interruption. Treat an interruption that results in less severe conditions than specified as an invalid test. Dry the test item and repeat the entire test procedure from the beginning. Treat any failure discovered during an undertest condition as a failure.
- (2) Overtest interruption. If more severe conditions than intended are applied and a failure results, repeat the test, if possible, on a replacement item. If no failure occurs, the test need not be repeated.
4.3.2 Interruption Due To Test Item Operation Failure
Failure of the test item(s) to function as required during operational checks presents a situation with several possible options.
- a. The preferable option is to replace the test item with a “new” one and restart from Step 1.
- b. A second option is to replace / repair the failed or non-functioning component or assembly within the test item with one that functions as intended, and restart the entire test from Step 1.
MIL-STD-810H
METHOD 512.6
NOTE: When evaluating failure interruptions, consider prior testing on the same test item, and the consequences of such.
4.4 Test Execution
The following steps, alone or in combination, provide the basis for collecting necessary information concerning the test item when partially or completely immersed in water.
4.4.1 Preparation for Test
4.4.1.1 Preliminary Steps
Before starting the test, review pretest information in the currently approved test plan to determine test details (e.g., procedures, item configuration, cycles, durations, parameter levels for storage/operation, etc.). (See paragraph 3.1 above.)
NOTE: Do not use sealing, taping, caulking, etc., except as required in the design specification for the materiel.
- a. If possible, when testing a shipping/storage container or transit case without the test items enclosed, remove all dunnage, packing, padding material, etc., that may absorb water before the test so that leakage can be detected. This option may not provide an adequate test of the container if the seals are not representatively stressed because of the absence of the contents.
- b. Secure items that may experience immersion when mounted on, or secured to a carrying platform, representatively. If representative of the real life situation, stacking is an acceptable method of restraining items under water.
4.4.1.2 Pretest Standard Ambient Checkout
All items require a pretest standard ambient checkout to provide baseline data. Conduct the pretest checkout as follows:
Step 1 Stabilize the test item temperature at standard ambient conditions.
Step 2 Conduct a complete visual examination of the test item with special attention to sealed areas, gaskets/seals, and structural integrity, and document the results. Take photographs, if appropriate. Verify that no free water is present; if so, dry.
Step 3 Conduct an operational checkout in accordance with the test plan and record the results.
Step 4 If the test item operates satisfactorily and seals appear to function as intended, proceed to Step 1 of the test procedure. If not, resolve the problem and restart at Step 1 of pretest checkout.
4.4.2 Procedure I - Immersion
Step 1 If weight gain is likely to be an acceptable method of determining leakage, weigh the test item.
Step 2 Three times immediately before the test, open and close (or remove and replace) any doors, covers, etc., that would be opened during normal use to ensure any seals are functioning properly and are not adhering to the sealing (mating) surfaces.
Step 3 Measure and record the immersion water temperature.
Step 4 Condition the test item as in paragraph 2.3.2.2 and record the conditioning temperature and duration. Leave the test item's sealed areas (where appropriate) open throughout the conditioning cycle. Also, materiel occasionally incorporates valves or venting devices that may or may not be opened in normal service use. If the test item incorporates such devices, open them throughout the conditioning portion of the test.
MIL-STD-810H
METHOD 512.6
- Step 5 Close all sealed areas and valves; assemble the test item in its test configuration and, as quickly as possible, immerse the test item in water so that the uppermost point of the test item is 1 ±0.1 m below the surface of the water, or as otherwise required by the test plan. The orientation of the test item should represent that of its expected in-service orientation. If several orientations are possible, select that which is most severe.
Step 6 Following a 30-minute immersion period (or as otherwise specified in the test plan), remove the test item from the water, wipe the exterior surfaces dry (giving special attention to areas around seals and relief valves) and, if applicable, equalize the air pressure inside by activating any manual valves. Be careful to not allow water to enter the test item while activating the manual valves.
Step 7 If appropriate, re-weigh the test item.
- Step 8 Open the test item and examine the interior and contents for evidence of, and quantity of any leakage and, if leakage occurred, for probable areas of entry. If using fluorescein use a blacklight to determine if any of the fluorescein dye has penetrated the test item.
Step 9 If appropriate; conduct an operational check of the test item and record results. See paragraph 5 for analysis of results.
4.4.3 Procedure II - Fording
Conduct the fording test in one of two ways: by towing or driving the test item through water at the appropriate depth, or by securing the test item in a tank and flooding the tank to the required depth. Unless otherwise justified, condition the test item as in paragraph 2.3.2.2.
- Step 1 If weight gain is likely to be an acceptable method of determining leakage, weigh the test item prior to the test.
- Step 2 With the test item in its fording configuration, ensure that any drain plugs or apparatus are closed, and either:
- a. Tow or drive the test item into the water at the required depth.
- b. Secure the test item in a watertight tank.
Step 3 If using the tank method; flood the tank to the required height above the bottom of the test item.
Step 4 Maintain the test item in the water for a duration as determined in paragraph 2.3.2.6.
Step 5 Either remove the test item from the water, or drain the water from the facility, and inspect the interior of the test item for evidence of free water.
- Step 6 Measure and record the amount of any free water, and the probable point(s) of entry. If appropriate, re-weigh the test item.