MIL STD 810H Test Method 506.6 – Rain Test Equipment

The purpose of MIL STD 810H test method 506.6 can evaluate materials that may be exposed to rain, water mist or water droplets during storage, transportation or operation. This method does not include standardized test procedures for rain erosion, because any related test procedures will depend on the materials used and the specific requirements of the factory used. Due to the limited size of the test equipment, it may be difficult to determine the effects of rainfall in the atmosphere, such as electromagnetic radiation and propagation. This method may not be sufficient to determine the effect of long-term exposure to rain or to evaluate materials that are only exposed to the surface with a slight condensation dripping rate (less than 140 L/m2/hr).

MIL-STD-810H-506.6-RTSEquipment Model
6000×2000×2000mm (L×W×H)Inner Room Size
7500×2200×2600mm (L×W×H)Machine Appearance
1300×500×500mm (L×W×H)Max Test Sample
Ø 1300 mmRotating Table
1~3 r/min|MIL-STD-810H Test Method 506.5 Rain TestingTurntable Speed
50 KG- Test SamplesTurntable Load-Bearing
Can be rotated 360 degrees, Meet the six different directions of the sample for testingRotation Direction of Turntable
The test place should prepares 0.6Mpa compressed airGas Source
MIL-STD-810 Rain Testing 0.1~0.2 MPaTap Water Pressure
Axial Fan DeviceFan System
Fangtong Frame + Tempered GlassThematic Structure
SUS304 Stainless SteelInner Room Material
SUS304 Stainless SteelDrip Tray Material
SUS304 Stainless SteelTurntable Table
SUS201 Stainless SteelFan Impeller Unit

MIL STD 810H Test Method 506.6 Rain Test Equipment

The rain test chamber from Wewon Environmental Chambers Co., Ltd. complies with the national military standard MIL-STD-810H procedure I rain test. It is used for military equipment or electronic products to simulate dynamic operation under various intensity rain conditions. Military equipment rain test methods and main Parameter, the rain test and drip test with wind source can be realized in a test room.

Determine the ability of enclosure seals of military equipment or electronic products to prevent rainwater penetration under rain conditions and their working efficiency during or after being exposed to rain, and evaluate waterproof work quality of product.

Water PressureAbout 276Kpa- Nozzles GenerateProcedure II Intensive Test
Raindrop DiameterGrid spraying grid in the range of Φ0.5mm~Φ4.5mm to achieve maximum surface coverage.
Nozzle LayoutThere should be at least one nozzle within every 0.56 square meters of rain-receiving surface area, and at least one nozzle at a distance of 48mm from the surface of the tested product.
Nozzle Spacing710 mm×710mm
Nozzle FeaturesAdjustable nozzle angle
Test TimeAt least 40min for each side, or more time can be set
Preset Test Time1S~9999H59M59S can be adjusted arbitrarily

It conforms to the national military standard MIL-STD-810H procedure II rain test, which is used to test large-scale (referring to the size of the test piece) equipment. When the rain and rain blowing device cannot be used, consider using the procedure II. The program does not simulate natural rainfall, but it can increase the reliability of the equipment’s waterproofness.

Horizontal Wind Speed≥18m/s to make raindrops blow the tested product evenly at a 45° angleProcedure I Wind Source Rain Test
Raindrop Diameter0.5~4.5mm
Drip Area1500×1500mm(W×D)
Needle Hole Distance20×20mm
Final Raindrop Speed9 m/s|MIL STD 810H Test Method 506.6 – Rain Test Method
Test TimeContinuous rainfall time 30min, or more time can be set.

The military standard 810 (MIL-STD-810) rain test system is mainly used to determine the effectiveness of the protective cover or protective shell to prevent rain seepage. Whether the rainwater drainage system is effective|The ability of the equipment to meet its performance requirements during or after exposure to rain|Physical damage to the equipment due to rain.

The purpose of this method is to help determine the following with respect to rain, water spray, or dripping water: Any physical deterioration of the materiel caused by the rain.Test Purpose
The effectiveness of protective covers, cases, and seals in preventing the penetration of water into the materiel. The effectiveness of any water removal system.
The capability of the materiel to satisfy its performance requirements during and after exposure to water. The effectiveness of protection offered to a packaged materiel.
Since any test procedure involved would be contingent on requirements peculiar to the materiel and the facility employed, a standardized test procedure for rain erosion is not included in this method|Wewon Environmental Chambers Co., Ltd. Copyrights
Where a requirement exists for determining the effects of rain erosion on radomes, nose cones, fuzes, etc., consider using a rocket sled test facility or other such facility.Limitations Notice
Because of the finite size of the test facilities, it may be difficult to determine atmospheric rain effects such as on electromagnetic radiation and propagation.
This method is not intended for use in evaluating the adequacy of aircraft windshield rain removal provisions.
This method doesn’t address pressure washers or decontamination devices.
This method may not be adequate for determining the effects of extended periods of exposure to rain, or for evaluating materiel exposed to only light condensation drip rates (lower than 140 L/m2/hr) caused by an overhead surface.
For this latter case, The aggravated humidity cycle of Method 507.5 will induce a significant amount of free water on both inside and outside surfaces.

Figure 506.6-1  Sample facility for steady state rain or drip test

Use this military environmental simulation testing method to evaluate materiel likely to be exposed to rain, water spray, or dripping water during storage, transit, or operation.Application Range
If the materiel configuration is the same, the immersion (leakage) test (Method 512.5) is normally considered to be a more severe test for determining if water will penetrate materiel.
There is generally no need to subject materiel to a rain test if it has previously passed the immersion test and the configuration does not change.
However, there are documented situations in which rain tests revealed problems not observed during immersion tests due to differential pressure.
Additionally, the immersion test may be more appropriate if the materiel is likely to be placed on surfaces with significant amounts of standing water.
In most cases, Perform both environmental engineering rain tests if appropriately identified in the life cycle profile|Military Standard MIL-STD-810H Rain Testing Equipment

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Step 1. If the temperature differential between the water and the test item is less than 10°C, either heat the test item to a higher temperature than the rain water (see paragraph 2.3.7) such that the test item temperature has been stabilized at 10 +2°C above the rain water temperature at the start of each exposure period (see paragraph 2.3.7), or cool the water. Restore the test item to its normal operating configuration immediately before testing.Procedure I – Rain and Blowing Rain
Step 2. With the test item in the facility and in its normal operating position, adjust the rainfall rate as specified in the test plan.
Step 3. Initiate the wind at the velocity specified in the test plan and maintain it for at least 30 minutes
Step 4. If required, operate the test for the last 10 minutes of the 30-minute rain. If the test item fails to operate as intended, follow the guidance in paragraph 4.3.2 for test item failure.
Step 5. Reheat test item. Rotate test item to expose it to the rain and blowing wind source to any other side of the test item that could be exposed to blowing rain in its deployment cycle.
Step 6. Repeat Steps 1 through 4 until all surfaces have been tested.
Step 7. Examine the test item in the test chamber (if possible), otherwise, remove the test item from the test facility and conduct a visual inspection. If water has penetrated the test item, judgment must be used before operation of the test item. It may be necessary to empty water from the test item (and measure the quantity) to prevent a safety hazard.
Step 8. Measure and document any free water found inside the protected areas of the test item.
Step 9. If required, Operate the test item for compliance with the requirements document, and document the results. See paragraph 5 for analysis of results.

Step 1. Install the test item in the test facility with all doors, louvers, etc., closed|MIL-STD-810H Method 506.6 Rain Test MachineProcedure II – Exaggerated
Step 2. Position the nozzles as required by the test plan or as indicated on MIL-STD-810 Figure 506.5-2.
Step 3. Spray exposed surfaces of test item with water for not less than 40 minutes per face.
Step 4. After each 40-minute spray period, inspect the interior of the test item for evidence of free water. Estimate its volume and the probable point of entry and document.
Step 5. Conduct an operational check of the test item as specified in the test plan, and document the results. See paragraph 5 for analysis of results.

Figure 506.6-2  Typical nozzle setup for exaggerated test, Procedure II (not intended for use when conducting Procedure I testing)

Step 1. Install the test item in the facility in accordance with Part One, paragraph 5.8 and in its operational configuration with all connectors and fittings engaged. Ensure the temperature differential between the test item and the water is 10°C or greater. If necessary, either raise the test item temperature or lower the water temperature to achieve the differential in paragraph 2.3.7, and restore the test item to its normal operating configuration immediately before testing.Procedure III – Drip
Step 2. With the test item operating, subject it to water falling from a specified height (no less than 1 meter (3 feet)) as measured from the upper main surface of the test item at a uniform rate for 15 minutes or as otherwise specified (see Figure 506.5-1 or Figure 506.5-3). Use a test setup that ensures that all of the upper surfaces get droplets on them at some time during the test. For test items with glass-covered instruments, tilt them at a 45° angle, dial up. If the test item fails to operate as intended, follow the guidance in paragraph 4.3.2 for test item failure.
Step 3. At the conclusion of the 15-minute exposure, remove the test item from the test facility and remove sufficient panels or covers to allow the interior to be seen.
Step 4. Visually inspect the test item for evidence of water penetration.
Step 5. Measure and document any free water inside the test item.
Step 6. Conduct an operational check of the test item as specified in the test plan, and document the results. See paragraph 5 for analysis of results.

Figure 506.6-3 Details of dispenser for drip test, Procedure III

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