MIL-STD-810 Humidity Testing for Custom Power Supplies

At Viable Power, we perform in-house MIL-STD-810 Humidity Testing (method 507.6) on our power supplies based on our clients’ needs and requirements. These tests ensure the dependability and durability of our ruggedized power supplies when operating in humid environments.

When performing our tests under MIL-STD-810, we check for the ability of the power supply to withstand the changes and effects of condensation and water while continuing to function correctly. After each humidity test, we perform a full acceptance test to verify the effect of humidity on the components and circuit boards.

MIL-STD-810 Humidity Testing Procedures

The 507.6 Humidity test method consists of two test procedures: Procedure I and Procedure II. To select the right test procedure, the customer takes into consideration the operational purpose of the equipment, the natural circumstances of exposure, the test data necessary to determine whether the operational purpose of the equipment has been achieved, and the duration of the test.

Procedure I – Natural (Open to the Environment) and Induced (Storage and Transit) Cycles

This test performs three cycles that represent natural and induced conditions. The Natural cycles consist of hot-humid, cyclic high humidity, and high humidity.

The induced cycles consist of induced constant high humidity and induced variable—induced hot-humid and high humidity.

Testing can take anywhere from 15 to 180 days based on the humidity cycle, system category, and whether conditions are induced or natural.

Viable Power_MIL-STD-810 Humidity Tested Power Supplies

Procedure II – Aggravated

This test exposes the custom power supply to more extreme humidity levels and temperatures than found naturally in the outside environment.
Results are quickly obtained using this test method—however, the observed effects may not accurately represent real-world conditions.

There are a minimum of ten mandatory 24-hour cycles for this test. However, the tester can increase cycle levels to increase confidence in the power supply and its ability to survive in high-humidity and high-temperature environments.

Viable Thermal Testing Chambers

Viable Power performs both test procedures in our state-of-the-art thermal testing chamber that has the following features:

  • Interior dimension of 76 cm sq (30” sq)

  • Humidity range of 10% to 98% relative humidity as limited by a +85°C (+185°F) maximum dry bulb and a +7°C (+45°F) minimum dewpoint

  • Temperature Range of -65°C to +190°C (-94°F to +375°F)

  • Control & Stability of ±0.5°C (±1°F) at steady state condition after stabilization

  • Live Load Testing Capacity of 3,500 watts at -40°C (-40°F), 2,600 watts at -54°C (-65°F) and 1,600 watts at -68°C (-90°F)

What Are the Effects of Hot and Humid Environments on Power Supplies?

High humidity and heat can cause chemical and physical changes to power supplies. A warm, humid environment can also lead to:

  • Changes in plasticity or flexibility

  • Decreased physical strength
  • Swelling of materials (sorption effect)
  • Electrochemical or chemical breakdown of surface coatings
  • Galvanic corrosion or oxidation of metals
  • Electrical short circuits
  • Degradation of hygroscopic materials
  • Composite material delamination

MIL-STD-810 Humidity Compliant Power Supplies

Viable Power is a well-established military power supply manufacturer. We proudly serve the armed forces (naval, aerospace, ground) and civil aviation industries worldwide. The humidity tests we conduct under MIL-STD-801H are qualification tests.

We utilize a stringent part selection process that helps ensure that our ruggedized power supplies can withstand the specified operating environments of our customers. We also include verification of the adequacy of the cooling arrangement in the verification process. Functional electrical testing is performed on the ruggedized power supply before and after the qualification tests.

You can trust Viable to ensure that all of our ruggedized power supplies have passed the most recent MIL-STD-810 Humidity Testing requirements and are ready for operational service. Contact us for more information about our capabilities and our custom power supply units.