MIL-STD 202 Steady State Humidity Testing
MIL-STD 202 humidity testing helps evaluate the influence of moisture and moisture vapor on the materials used in components. This environmental test continuously exposes the specimen to high relative humidity at an elevated temperature. These conditions impose a vapor pressure on the material, which constitutes the force behind the moisture migration and penetration. Hygroscopic materials are sensitive to moisture, and deteriorate rapidly under humid conditions.
Absorption of moisture by many materials exposed to humid environments, results in swelling. This destroys their functional utility, and causes loss of physical strength and changes to important mechanical properties. Insulating materials that absorb moisture may suffer degradation of their electrical properties. This method, though not intended to simulate tropical tests, is of use in determining moisture absorption of insulating materials.
Keystone Compliance is a humidity testing lab with significant MIL-202 humidity testing experience. The following information is extremely technical in nature. It provides a summary of the humidity compliance testing requirements of MIL-STD 202G humidity section.
What is the Procedure for Method 103B?
All testing should occur in a humidity laboratory, equipped with the appropriate testing chambers and accessories. The chamber and accessories should be constructed and arranged so as to avoid condensate dripping on test materials. They should also ensure that the specimens are exposed to circulating air.
Begin by conditioning the specimens in a dry oven at 40°C plus or minus 5°, for 24 hours. At the end of this period, make the specified measurements. For exposure, place the specimens in a chamber for the period specified in one of the following test conditions. Subject them to a relative humidity of 90 to 95 percent and a temperature of 40° ±2°C.
Test Condition | Length of Test (Hours) |
---|---|
A | 240 |
B | 96 |
C | 504 |
D | 1,344 |
How and When Should the Final Measurements of the Test Materials be Made?
High humidity measurements are made after the exposure period is complete, while the specimens are still in the chamber. These measurements may be compared to the initial measurements, when applicable.
Measurements for after the drying period are made after completing the exposure period or following measurements at high humidity if applicable. The specimens are conditioned at room ambient conditions for 1-2 hours unless otherwise specified. After conditioning, the specified measurements are performed at room ambient conditions.
What Physical and Chemical Problems Might Material Experience When Exposed to Humidity?
It is important to ensure that no physical and/or chemical problems of materials arise during testing. The following are some of the most common problems that can occur. Sealed containers can rupture, deform, or explode. Engines may start erratically.
Low-density materials risk changes to their physical and chemical properties. Hermetic seals may fail, and lubricants may evaporate. For heat, lubricants risk evaporation and gases and fluids can leak from gasket-sealed enclosures.
What Laboratory Offers the Best Humidity Testing?
Keystone Compliance has been recognized as one of the best humidity labs in the country. Our facilities consist of state of the art equipment to provide a variety of testing services. Our test engineers are knowledgeable in the requirements of humidity and temperature testing.
Are you looking to get a humidity certification for your product? Keystone provides a variety of compliance testing for commercial, military, and aerospace materials. Contact us to learn why so many manufacturers rely on Keystone Compliance for all their compliance testing needs.
Looking for other MIL-STD-202 compliance tests? Click on a link below to learn more about the other test methods.
- MIL-STD-202 Test Method 101 Salt Atmosphere (Corrosion)
- MIL-STD-202 Test Method 103 Humidity (solid state)
- MIL-STD-202 Test Method 104 Immersion
- MIL-STD-202 Test Method 105 Barometric Pressure
- MIL-STD-202 Test Method 106 Moisture Resistance
- MIL-STD-202 Test Method 107 Thermal Shock
- MIL-STD-202 Test Method 108 Life (at elevated ambient temperature)
- MIL-STD-202 Test Method 109 Explosion
- MIL-STD-202 Test Method 110 Sand and Dust
- MIL-STD-202 Test Method 111 Flammability (external flame)
- MIL-STD-202 Test Method 112 Seal
- MIL-STD-202 Test Method 201 Vibration
- MIL-STD-202 Test Method 203 Random Drop
- MIL-STD-202 Test Method 204 Vibration, High Frequency
- MIL-STD-202 Test Method 206 Life (rotational)
- MIL-STD-202 Test Method 207 High-Impact Shock
- MIL-STD-202 Test Method 208 Solderability
- MIL-STD-202 Test Method 209 Radiographic Inspection
- MIL-STD-202 Test Method 210 Resistance to Soldering Heat
- MIL-STD-202 Test Method 211 Terminal Strength
- MIL-STD-202 Test Method 212 Acceleration
- MIL-STD-202 Test Method 213 Shock (specified pulse)
- MIL-STD-202 Test Method 214 Random Vibration
- MIL-STD-202 Test Method 215 Resistance to Solvents
- MIL-STD-202 Test Method 216 Resistance to Solder Wave Heat
- MIL-STD-202 Test Method 217 Particle Impact Noise Detection
- MIL-STD-202 Test Method 301 Dielectric Withstanding Voltage
- MIL-STD-202 Test Method 302 Insulation Resistance
- MIL-STD-202 Test Method 303 DC Resistance
- MIL-STD-202 Test Method 304 Resistance-Temperature Characteristic
- MIL-STD-202 Test Method 305 Capacitance
- MIL-STD-202 Test Method 306 Quality Factor
- MIL-STD-202 Test Method 307 Contact Resistance
- MIL-STD-202 Test Method 308 Current-Noise Test for Fixed Resistors
- MIL-STD-202 Test Method 309 Voltage Coefficient of Resistance Determination Procedure
- MIL-STD-202 Test Method 310 Contact-Chatter Monitoring
- MIL-STD-202 Test Method 311 Life, Low Level Switching
- MIL-STD-202 Test Method 312 Intermediate Current Switching