MIL-STD-810 Test Method 521 Icing/Freezing Rain
The purpose of the MIL-STD-810 icing test is to evaluate the effect of icing on materials. As a MIL-STD-810 certified lab, we realize the importance of icing/freezing rain method 521 testing. Meeting the MIL 810 test method 521 icing test requirements can be difficult. Keystone Compliance understands the challenges and guides companies through the process.
Keystone Compliance has a reputation of helping customers achieve their MIL-STD product certifications. We provide comprehensive reports shortly after completion of the MIL-810 standard testing. Keystone creates an accurate test plan to eliminate expensive over-testing. We take a consultative approach throughout the entire test program. This means that we are in constant communication throughout the entire test process, from start to finish.
Request a quote to see why so many companies partner with Keystone Compliance. Have a question about icing and freezing rain testing? Contact us or call (724) 657-9940 and we will determine the best course of action.
The Importance of MIL-810 Icing/Freezing Testing
This MIL-STD-810 enclosure seal test evaluates the effectiveness of de-icing equipment and techniques. This includes prescribed means to be used in the field.
The application of this MIL-STD 810 compliance method is to develop ice accretion from sea splash or spray. However, the ice thickness may need to be modified to reflect the lower density of the ice.
How MIL-STD-810 Test Method 521 Affects Products
The tailoring process will help determine where icing/freezing rain is anticipated to occur within the materials life cycle. When ice removal is required before operation, use integral deicing equipment or expedients normally available within the field.
Deicing equipment is used to evaluate the effectiveness and potential for damage. This damage may degrade the materials performance.
Ice formation can prevent material operation and survival. Ice formation may also affect the safety of operating personnel. The following typical problems listed below help determine if this method is appropriate for the material being tested. Note that this icing lab testing list is not intended to be all-inclusive.
- Binds moving parts together
- Adds weight to radar antennas, aerodynamic control surfaces, helicopter rotors, etc.
- Increases footing hazards for personnel
- Interferes with clearances between moving parts
- Induces structural failures
- Reduces airflow efficiency as in cooling systems or filters
- Provides a source of potential damage to material from employment of mechanical, manuel, or chemical ice removal measures
- Reduces efficiency of aerodynamic lifting and control surfaces
- Reduces aircraft stall margins
Information on this MIL-STD 810 Lab and Military Standard Testing Method
Use the anticipated life cycle sequence of events as a general sequence guide. However, there are two approaches to using this MIL-810 test method among other methods.
The first approach to the MIL 810 method 521 testing is to conserve the test item by applying the least damaging environments first. For the first approach, apply the icing and freezing rain following the rain tests but prior to the salt fog tests.
The second approach consists of applying environments to maximize the likelihood of disclosing synergistic effects. For this approach, subject the icing test item to the dynamic tests prior to conducting the icing/freezing test.
Though this MIL-STD 810 test method only has one procedure, there are various conditions that may be selected. Before conducting this ip code test, it is important to select specific procedure variations based on the requirements documents.
A buildup of ice occurs in four principal ways. First, from rain, drizzle, or fog falling on the material whose temperature is at or below freezing. Second, from sublimation. From freezing rain or freezing drizzle falling on material. Lastly, from sea spray and splash that coats material when the material temperature is below freezing.
Types of ice – There are two types of ice commonly encountered when proceeding with this icing freezing rain lab test.
Rime Ice – is a white or milky and opaque granular deposit of ice formed by a rapid freezing of supercooled water drops as they fall upon the exposed object. Rime ice is lighter, softer and less transparent than glaze with two variations: hard rime and soft rime.
Glaze Ice – This coating of ice is generally clear and smooth but usually contains some air pockets formed on exposed objects by the freezing of a film supercooled water vapor. Since glaze ice is more difficult to remove, it is structurally a more significant factor.
Water Delivery Rate – The objective of this MIL-810 icing test variation is to produce a clear, uniform coating of glaze ice. Any delivery rate that produces such ice is acceptable. However, the water delivery rate is suggested at 25mm/h
Water Delivery Method – Nozzle arrays that direct spray to the top, sides, front and rear of the test item, a single nozzle directing spray over the appropriate surfaces of the test item. Nozzle arrays that spray straight down onto the test item are all acceptable. However, it is acceptable as long as the water is delivered in a uniform way.
Droplet Size – The droplet size may vary and range from 1.0 mm to 1.5 mm diameter
Ice Thickness – Unless specifically measured data is available, the following ice thicknesses are recommended:
6 mm – represents general conditions, light loading
13 mm – represents general conditions, medium loading
37 mm – represents heaving ground loading and marine mast loading
75 mm – represents extremely heavy ground loading and marine deck loading
Limitations of the Icing Compliance Method
Within this MIL-810 standard method, some limits are imposed and must be noted when applying the tailoring process. This method is not supposed to simulate snow conditions or ice buildup on aircraft through supercooled clouds. Though frost occurs naturally, these effects are considered less important. They are not expected to be addressed within test method 521, icing freezing rain test.
This MIL-STD-810 standard may also not be suitable for the assessment of aerial/antenna performance. Lastly, other conditions that are not included within this MIL-810 icing freezing rain test are the icing effects from falling, blowing or recirculating snow, wet snow or slush.
Keystone Compliance Provides Expert MIL-810 Icing/Freezing Rain Testing
Our team strives to give our customers more time and energy on product development instead of testing. Keystone has a full lab of test equipment which permits us to provide short lead times on scheduling.
Ready to get started? We are. Contact us to see why so many companies work with us to achieve their military standard testing needs.