Testing

Using the ANSI/IEC 60529-2020 standardization, the Ingress Protection rating can be determined for an enclosure. The desired Ingress Protection rating for the device is to meet a rating of 67. To reach this level of protection, the enclosure must be dustproof and survive a water submersion test to a depth of one meter for 30 minutes. If the device can still function as intended after the submersion, the test is deemed a success. To further the protection of the phone housing, an altered test will commence. The modified tests will contain all prior specifications. The first altered test will have the phone housing heated to 120 degrees Fahrenheit (49 degrees Celsius) before being submerged in the water. The second modified test will cool the phone to 0 degrees Fahrenheit (-18 degrees Celsius) before being submerged. These tests are devised to replicate the environmental extremities that a phone could encounter during its operational lifecycle. The overarching objective is to validate the housing's capability to preserve its dustproof and water-resistant attributes amidst thermal expansion and contraction induced by these conditions.

Ingress Protection Test: 3d Printed Phone Housing

For the Ingress Protection Test: 3d Printed Phone Housing the phone housing was submerged to a depth of nine inches for thirty minutes to evaluate its resistance to water ingress. Upon completion of the test, it was observed that water had leaked into the housing. However, the analysis concluded that the leakage was attributable to the material of the housing rather than its design. An equation (Pressure=density*gravity*depth) had been applied to estimate the pressure that the housing needed to withstand, suggesting that the design was theoretically capable of resisting such pressure. The discrepancy between the anticipated outcome and the actual result was attributed to the material properties; the 3D printed plastic used in the test was less robust compared to the aluminum assumed in the calculations. This difference in material strength was identified as the critical factor leading to the observed leakage.

Figure 1: Test module submerged in the testing container.

Figure 3: Water leakage within the test module after testing

Figure 2: Test module prior to testing

Instron Test: Normal Force

The Instron Test: Normal Force assessed the ability of a phone housing prototype to withstand a 100 lb load without permanent deformation. Utilizing the Instron machine, the test was meticulously prepared, with supports securing the housing and careful alignment of components. Monitoring the force applied, the operator promptly engaged the emergency stop (e-stop) upon reaching the 100 lb threshold. Data collected indicated a slight deflection of 0.09 inches during testing, but the housing returned to its original shape upon force removal, confirming its capacity to endure the specified load without permanent deformation. The entirety of the test, from setup to teardown, proceeded flawlessly, validating the prototype's design and meeting the desired criteria.

Figure 4: Test module

Figure 5: Test module under load

Video of Instron Test: Normal Force

Data:

Ingress Protection Test: Aluminum Prototype

For the Ingress Protection Test: Aluminum Prototype, the phone housing was submerged to a depth of 38 inches (approximately one meter) for 30 minutes to evaluate its resistance to water ingress. Upon completion of the test, it was observed that two out of the three modules had leaked water into the housing. However, one module demonstrated no water ingress, indicating that the design was potentially adequate. This outcome was determined by conducting both a visual inspection and weighing the modules before and after submersion to detect any water ingress. The pressure the housing needed to withstand was estimated using the equation Pressure=density×gravity×depth. The variation in outcomes among the prototypes was attributed to assembly errors. All components must be meticulously assembled to ensure the device's maximum resistance to water ingress. It was theorized that the assembly process improved over time, as the third module, which experienced no ingress, was assembled more effectively. This improvement in assembly likely resulted from the assembler's increased familiarity with the process, leading to the final module being water-tight, while the initial modules had minor, unnoticed flaws. Despite these assembly issues, the data indicated that the design met the requirements set by the Ecophone team.