What Is a Drop Test?

Drop Test - What Is It?

During the lifetime of an electronic product, it is likely that at some point it will be dropped. When an electronic product is dropped, its ability to withstand damage and continue functioning properly can significantly affect repair or replacement costs, impacting the total cost of ownership. Therefore, a product’s durability and resistance to physical damage play a crucial role in determining long-term expenses for the user, beyond the initial purchase price.

We examine the ruggedness, or resistance to damage, of electronic products when dropped. The ruggedness of electronic products is important because it determines how well they can withstand repeated impacts without malfunctioning or breaking. By understanding a product’s durability through multiple drops, manufacturers can enhance design features to improve longevity and user satisfaction.

The intensity of the drop can vary from extreme (occurring less frequently) to the more commonly occurring lower intensity drop, referred to as a “tumble”. 

Currently, there is no established set of standards that define the testing criteria for evaluating the durability of electronic devices. This absence of standardized benchmarks means that companies must be proactive in identifying and understanding the various standards that can be applied to assess the robustness of their products. In doing so, they should pay close attention to the key factors that contribute to the ruggedness of an electronic product. These factors may include the device’s ability to resist physical impacts, operate under extreme temperatures, withstand exposure to moisture and dust, and endure prolonged periods of use without degradation in performance. By gaining a comprehensive understanding of these elements, companies can better ensure their products meet the necessary durability requirements for their intended applications and environments.

When evaluating a product’s durability, it is essential to ensure that the methods used to specify its resistance to damage are aligned with how customers will actually use the product. This means that the tests or ratings assigned to measure durability must realistically reflect the conditions and scenarios that occur in real-life usage. Customers may have different use cases, meaning they might use the product in various ways that impose different levels of stress or strain. Therefore, equating the testing methods with these use cases is crucial. If the testing scenarios do not accurately represent how the product will be used, then the ratings might not be reliable indicators of the product’s true ability to withstand wear and tear over time. In essence, for durability ratings to be meaningful and valid, they must be based on tests that simulate real-world conditions effectively.

When evaluating an electronic product’s ruggedness when dropped, it is important to understand:

• The various standards of drop testing, along with their limitations.
• How the surface to which the product is dropped can greatly affect the cumulative damage a product may sustain.

Devices often face small, frequent drops. It’s crucial to test them to see if they can handle repeated tumbles without breaking or malfunctioning. This helps ensure the product can withstand daily use and accidental drops.

How Is Product Drop Testing Conducted to Ensure Durability and Reliability?

Drop testing evaluates a product’s ability to withstand being dropped. This is important because, in real life, products might accidentally fall during their use. To ensure reliability, products should be designed to survive these accidental drops without sustaining damage. It’s important to remember that products are not meant to be dropped on purpose; the drop tests are just a way to simulate real-world accidents.

Before the drop test is conducted, several factors must be clearly defined. These include the number of times the product will be dropped, the height from which it will be dropped, and the type of surface it will hit when it lands. By specifying these details, the test can accurately reflect potential real-world scenarios, helping manufacturers improve product durability.

During the test, a product is dropped in a “free fall” manner a set number of times, from a fixed height, to a flat surface. This means that the product is simply released from a stationary position without any initial push or direction, allowing it to fall naturally under the influence of gravity. Objects are dropped from a stationary position and are not thrown or directed.

The test unit is placed in a specified orientation (for example, display down, display up, on its side, etc.) for each drop.

After each drop, the unit is examined for damage. Units exhibiting a major loss in functionality, such as problems with powering on, capturing data, and allowing data entry, after drop testing do not pass the test.

Several factors increase the severity level of testing, including increasing the required number of drops, height above the surface, the hardness of the drop surface, and decreasing the temperature of the unit during a drop (as product becomes more rigid with respect to impact).

What Are the Drop Standards?

Various drop standards or drop specification references are often used when testing devices. These include Zebra internal drop standards, U.S. Military Standard (MIL-STD), and competitive drop standards/specification references.

Zebra Internal Drop Testing

Zebra’s internal drop testing standards require that:

• A unit is dropped 36 times - 6 times per side.
• The test is repeated on 3 different units across the device’s operating temperature range (at high, low, and room temperature).
• Test units are operational (powered on) when dropped.
• Drop heights range from 4 to 8 feet.

If the device powers off or reboots and data is lost during testing, the device is deemed to have failed the drop test.

What Is Mil-Std-810 Certified?

U.S. Military Standard, MIL-STD-810G 516.6, defines a process by which devices are dropped 26 times, on all faces (sides), corners, and edges.

• Distributed over 5 test units, the unit test includes 8 corner drops, 12 edge drops, and 6 face drops.
• Units are dropped at test method-defined temperatures.
• Units are non-operational (powered off) for the drop test.

Different Options Within MIL-STD Drop Testing and Their Effects on Products

MIL-STD provides options for passing the drop test. When a product is specified to meet MIL-STD-810G 516.6 drop standards, it is important to compare the product specifications directly to the many options of the military standard to see the exact details of the drop tests, and therefore better understand the severity of the testing; and consequently, the true ruggedness of the device.

Various options within MIL-STD drop testing affect the severity of a test, including:

• Height of Drop: Devices can be dropped from varying heights within MIL-STD specifications. Higher drops produce greater impacts.
• Surface Material: Surface material to which units are dropped, such as plywood over concrete, vinyl tile over concrete, concrete, or steel. Harder and rougher surfaces produce higher impacts during drop tests.
• Temperature: Drop tests can be performed at temperatures above the operating temperature of the device or just at room temperature, depending on the military specification option picked. Drop tests occurring over a wider temperature range are more difficult to pass because components are more prone to physical failures at temperature extremes (such as cracking at cold temperatures and swelling at hot temperatures).

Competitive Drop Standards or Specification References

May specify more than just the drop height:

• The drop surface, number of drops, and temperature range may be included or excluded from the specifications.
• The temperature range of drop tests can also be omitted.

Factors typically not defined include:

• Number of units dropped to pass the test.
• Definition of the unit’s power state (on/off)

Drop Standards Summary

Not all drop specifications are the same, when assessing drop performance, one should look at these factors:

• What drop standards (for example, Zebra internal or MIL-STD810G 516.6) or specification references are used
• Drop height
• Drop surface
• Drops over a range of temperatures
• Number of drops, if listed
• Whether a tumble specification is also defined.

We have created a more detailed guide about Drop-testing.