International Standard IEC 60529 outlines an international classification system that describes the sealing characteristics of electrical equipment. The classification system defines the level of protection provided by enclosures to prevent the ingress of foreign objects and moisture into the electrical equipment. The classification system uses the IP code, or Ingress Protection code, to define the level of seal. The IP code uses a system of two numerical digits to define the level of both foreign object and moisture protection. Although the IP classification is primarily used for establishing the level of seal in electrical equipment, it is adapted herein for determining the level of seal in passive electrical components.
Degrees of Protection (Foreign Bodies) 1st Digit
The first digit of the IP code indicates the degree of protection against solid foreign objects from entering the electrical device. The table below outlines the level of protection against foreign objects for each level.
Degrees of Protection (Moisture) 2nd Digit
The second digit of the IP code indicates the degree of protection against the ingress of various forms of moisture (e.g. drip, spray, submersion, etc.) into the component. Tests to determine the level of protection are carried out with fresh water and do not take into account the use of solvents.
Description of Protection Level 1st Digit (Foreign Bodies)
0 = Not protected 1 = Protected against solid foreign objects of 50 mm diameter and greater 2 = Protected against solid foreign objects of 12,5 mm diameter and greater 3 = Protected against solid foreign objects of 2,5 mm diameter and greater 4 = Protected against solid foreign objects of 1,0 mm diameter and greater 5 = Protected from the amount of dust that would interfere with normal operation 6 = Dust tight
Description of Protection Level 2nd Digit (Moisture)
0 = Not protected 1 = Protected against vertically falling water drops 2 = Protected against vertically falling water drops when enclosure is tilted up to 15 ° 3 = Protected against water sprayed at an angle up to 60 ° on either side of the vertical 4 = Protected against water splashed against the component from any direction 5 = Protected against water projected in jets from any direction 6 = Protected against water projected in powerful jets from any direction 7 = Protected against temporary immersion in water 8 = Protected against continuous immersion in water, or as specified by the user
MIL-STD-810 (MIL-STD (810F Method 512.4 Leakage)
The United States Military Standard referred to as MIL-STD-810, “Department of Defense Test Method Standard for Environmental Engineering Considerations and Laboratory Tests” emphasizes tailoring an equipment’s environmental design and test limits to the conditions that it will experience throughout its service life, and establishing chamber test methods that replicate the effects of environments on the equipment rather than imitating the environments themselves. The MIL-STD-810 test series are approved for use by all departments and agencies of the United States Department of Defense (DoD). Although prepared specifically for DoD applications, the standard may be tailored for commercial applications as well.
Scope of the standard
The military standard MIL-STD-810 test series addresses a broad range of environmental conditions that include: low pressure for altitude testing; exposure to high and low temperatures plus temperature shock (both operating and in storage); rain (including wind blown and freezing rain); humidity, fungus, salt fog for rust testing; sand and dust exposure; explosive atmosphere; leakage; acceleration; shock and transport shock (i.e., triangle/sine/square wave shocks); gunfire vibration; and random vibration. The environmental management and engineering processes described within MIL-STD-810 can be of enormous value to generate confidence in the environmental worthiness and overall durability of a system design. Still, there are limitations inherent in laboratory testing that make it imperative to use proper engineering judgment to extrapolate laboratory results to results that may be obtained under actual service conditions. In many cases, real-world environmental stresses (singularly or in combination) cannot be duplicated in test laboratories. Therefore, users should not assume that a system or component that passes laboratory testing also would pass field/fleet verification trials.
Lead standariazation agency
The military standard MIL-STD-810 series of test methods are issued by the United States Army’s Developmental Test Command who is chartered under the Defense Standardization Program (DSP) with maintaining the functional expertise and serving as the DoD-wide technical focal point for the standard. The current document revision (2009) is Revision G (i.e. MIL-STD-810G) which was issued on October 31, 2008. It superseded Revision F (MIL-STD 810F) released on January 1, 2000 and which was last updated on May 5, 2003.
Test methods and examples
The MIL-STD-810 test series contains environmental laboratory test methods that are applied using specific test tailoring guidelines described within the standard. Note that test methods are not to be called out in a “blanket” fashion nor applied as unalterable routines, but are to be selected and tailored to generate the most relevant test data possible, and incorporated into a system’s final design specification, as specified by the Procuring Agency. The selected test methods are designed to simulate specific environmental conditions anticipated to be encountered over the life of the system.