Additional testing was performed on the vented test enclosure to make sure that changes in RH can reliably be attributed to true ingress events, and false alarms does not occur due to normal fluctuations in the ambient humidity. First, the vent was submerged in water to verify the integrity of the waterproof vent. The vent prevented any water from entering the test enclosure and slowed down the moisture exchange. As a result, the RH remained essentially flat (see Figure 5-9).

For the second test, the vented enclosure was acclimated to indoor ambient conditions of about 23.5°C and 44%RH. Then, the enclosure was closed and placed inside of the environmental test chamber, which was preset to high humidity conditions of 90%RH at 25°C. The HDC3020 was observed to see how fast the RH reading can increase. As shown in Figure 5-10, the RH 10-second slew rate did not increase over time as quickly as a true water ingress event, and remained much lower than the threshold. This demonstrates that with a properly vented enclosure, this is possible to distinguish leaks from normal humidity increases without triggering a false alarm.