MIL-STD-810 Contamination By Fluids Testing Overview [Method 504.3]

What is MIL-STD-810 contamination by fluids testing?

According MIL-STD-810H, the latest iteration of the standard, the purpose of contamination by fluids testing, also known as Test Method 504.3 or fluid contamination testing, is to assess the effects that temporary exposure to certain liquids has on a system.

Test engineers usually test for this method if there is a high probability that a customer’s system will encounter accidental or intentional fluid contamination in the field. The results help them determine whether any product design changes need to be made to tailor the system to its service environment.

Regardless of whether exposure occasionally occurs, intermittently occurs or occurs over an extended period, certifying a system to Test Method 504.3 offers considerable protection from any contaminating fluids encountered or applied during a system’s life cycle.

Exposure of material to contaminating fluids may either temporarily or permanently impair the operation of the material by changing the physical properties of the materials composing it.

- Excerpt from MIL-STD-810H

In the field, fluid contamination may occur from exposure to fuels, hydraulic fluids, lubricating oils, solvents and cleaning agents, de-icing fluids and anti-freeze, runway deicers, insecticides, disinfectants, coolant, dielectric fluid and fire extinguishants.

It’s important to note that Test Method 504.3 does not assess the ability of a system to perform during continuous fluid exposure, nor does it test for electrolytic corrosion or corrosion due to human perspiration.

Photo: MIL-STD-810's Test Method 504.3 assesses occasional, intermittent and extended fluid contamination.

What are the different fluid contamination testing procedures?

MIL-STD-810 fluid contamination testing has one testing procedure but three distinctive exposures: occasional contamination, intermittent contamination and extended contamination.

With occasional exposure, a system is exposed for 5-10 minutes at standard ambient conditions, unless a test temperature akin to that of the system’s real-world environment is specified.

With intermittent exposure, a system is continuously exposed for eight hours and left to air dry for 17 hours at standard ambient temperature.

With extended contamination, an item is continuously exposed for at least 24 hours. As with occasional exposure, standard ambient temperature is used unless otherwise specified, at which point the test item is kept in the specified temperature for eight hours before the temperature is changed to standard ambient for the remainder of the testing period.

How is MIL-STD-810 fluid contamination testing performed?

A fluid contamination facility or setup should include an enclosure and temperature control mechanism designed to maintain test items at specified temperatures.

A system is placed into a tank within the enclosure and exposed to the selected contaminants. The chemicals are typically applied to the system by immersing, spraying or brushing, depending on the type of exposure.

Photo: Under MIL-STD-810, anything from cleaning agents to gasoline and hydraulic oil is used for fluid contamination testing.

What types of test fluids are used in fluid contamination testing?

MIL-STD-810 fluid contamination testing involves the application of common chemicals used regularly in military and industrial environments.

MIL-STD-810H lists 30 general test fluids for use with Test Method 504.3. These fluids include various lubricants, engine oil, gasoline, insect repellent, antifreeze, water, hydraulic fluids and damping fluids.

For a complete list of fluids, see Table 504.3-I in our MIL-STD-810H fluid contamination testing PDF linked at the beginning of this blog post.

What are the systematic effects of fluid contamination?

There are various physical, chemical and electrical effects that contaminating fluids can have on a system.

Test Method 504.3 may be one of the easier, shorter MIL-STD-810 test methods to perform, but the consequences of fluid contamination are numerous and widespread.

Test engineers are encouraged to consider the following examples of potential damage when deciding whether fluid contamination testing is necessary:

Physical

• Shattering of glass vials and optical material
• Binding or slackening of moving parts
• Cracking of solid pellets or grains in explosives
• Differential contraction or expansion rates or induced strain rates of dissimilar materials
• Deformation or fracture of components
• Cracking of surface coatings
• Seal or gasket failures
• Failure of insulation protection
• Condensation of water onto cold surfaces suddenly exposed to higher ambient temperatures at "high relative humidity" - can cause frosting on optical surfaces - can cause corrosion on vulnerable surfaces
• Differential contraction or expansion rates or induced strain rates between surface and interior portions of thermally massive constructs.
• Packaging failure
• Crazing or swelling of plastics and rubbers
• Adhesion failures
• Paint / legend removal

Chemical

• Separation of constituents
• Failure of chemical agent protection
• Leeching of antioxidants and other soluble materials
• Corrosion
• Melting or decomposition

Electrical

• Changes in electrical and electronic components
• Electronic or mechanical failures due to rapid water or frost formation
• Excessive static electricity
• Interruption of electrical continuity
• Increase in electrical resistance due to thermo-mechanical fretting corrosion

Photo: When it comes to protecting your rugged server or workstation in harsh or risky environments, it's better to be safe than sorry. Always ask your rugged server manufacturer about the MIL-STD-810 tests a system has undergone before buying.

Conclusion

MIL-STD-810 contamination by fluids testing is a relatively short and simple method that can be used to protect your system from a variety of chemicals and solutions in the field.

Whether exposure is intentional or accidental, occasional, intermittent or prolonged, this test method has you covered.

Trenton Systems performs shock, vibration, temperature, and humidity testing on its rugged servers, blade servers, and workstations in-house, but we partner with local compliance testing facilities that can accommodate testing requests beyond our capabilities.