SNAA420A June   2025  – August 2025 HDC3020 , HDC3020-Q1 , HDC3021 , HDC3021-Q1 , HDC3022 , HDC3022-Q1 , HDC3120 , HDC3120-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Motivation
    2. 1.2 The Physics of Humidity and Water Ingress
  5. 2Test Methodology
  6. 3Assumptions
  7. 4Proposed Algorithm Using Slew Rate Threshold
  8. 5Test Results
    1. 5.1 Test Results at Indoor Ambient Conditions
    2. 5.2 Test Results at Hot and Cold Temperature Conditions
    3. 5.3 Vent Submersion and Air Exchange Tests
  9. 6Summary
  10. 7References
  11. 8Revision History

3 Assumptions

For this water leak detection experiment, a few assumptions were made to narrow the scope of the testing:

  • A vent was incorporated in the enclosure for pressure equalization. This prevents pressure buildup as internal temperature changes. In the experiment, TI used a waterproof vent to allow dampened air exchange with the atmosphere, allowing for pressure equalization while blocking liquid water. While this constitutes a semi-open system, this assumption still allows the experimental results to apply to closed systems. Nominally sealed systems do not develop internal pressure. Even a closed system that was hermetically sealed at atmospheric pressure, when punctured during a leak event, does not see a pressure change occur.

  • The system is started in a dry, known-good state at the beginning of each test. The assumption is that no water is present in the enclosure at time zero of the algorithm. The tested enclosure was completely dry at the start of every experiment trial. Determining if a system was already wet before startup is outside the explicit scope of these tests. Water ingress is a single event.
  • Temperature is held constant during each test. TI assumes no significant heating or cooling occurs while a leak event is in progress. For the high- and low-temperature tests, the water was previously conditioned to the target temperature to avoid introducing any temperature-change effects on humidity.