SNAU265D June   2021  – February 2025 HDC3020 , HDC3020-Q1 , HDC3021 , HDC3021-Q1 , HDC3022 , HDC3022-Q1 , HDC3120 , HDC3120-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1HDC3x Devices
    1. 1.1 HDC3x2x Package Comparison
    2. 1.2 HDC3020 in WSON
    3. 1.3 HDC3021 in WSON
    4. 1.4 HDC3022 in WSON
    5.     HDC3120 in WSON
  5. 2Storage and Handling Guidelines
    1. 2.1 Exposure to Contaminants
    2. 2.2 Chemical Analysis
      1. 2.2.1 Saturation and Recovery Tests
      2. 2.2.2 Long-Term Exposure
    3. 2.3 Packaging and Storing
      1. 2.3.1 Assembly
      2. 2.3.2 Application in Extreme Environment
  6. 3Programming the HDC3020
    1. 3.1 The Functional Modes
    2. 3.2 Trigger-On Demand
    3. 3.3 Auto Measurement
    4. 3.4 Programming the CRC
      1. 3.4.1 CRC C Code
    5. 3.5 Example Code
    6. 3.6 Condensation Removal
    7. 3.7 Offset Error Correction
      1. 3.7.1 Offset Error Correction Example With a Fingerboard
  7. 4References
  8. 5Revision History

2.2.2 Long-Term Exposure

Four samples per chemical were submitted for a long-term exposure test. These devices were exposed to gaseous forms in a sealed chamber for 21 days. Table 2-2 shows the chemicals in this test.

Table 2-2 List of Chemicals for the Long-Term Exposure Test
Chemical Concentration (ppm) Observable Damage
Toluene 298 – 322 None
Xylene 108 – 131 None
Butyl Acetate 200 – 220 None
Formaldehyde 3 – 5 None
Sulfur Dioxide 5 None
Ethanol 862 – 1003 None
Methanol 195 – 260 None
Ammonia 34 – 35 None
Cigarette Smoke Saturated Staining and coating

For the devices exposed to cigarette smoke, smoke from a cigarette was blown into a chamber until it was saturated and the devices were not visible. Half a cigarette was used each time to saturate the chamber and the smoke inside the chamber was refreshed every day.

For the rest of the chemicals, the chemicals were administered using a syringe. The gases were refreshed every seven days by the chemist to ensure the concentration of the gases remained high.

Overall, most of the chemicals had an increased negative gain, but there were no significant offset changes on these parts. Figure 2-3 and Figure 2-4 show the results for these sweeps.

HDC3020 Long-Term Exposure Results Figure 2-3 Long-Term Exposure Results
HDC3020 Long-Term Exposure Results Figure 2-4 Long-Term Exposure Results

Figure 2-5 shows that exposure to cigarette smoke resulted in a huge negative gain and the RH error of these parts varied from 25% to –50% between 10% to 90% RH setpoints. The boards also had severe discoloration and visible residue on the sensor opening. The sensor was cleaned using air, but the device performance did not recover.

HDC3020 Long-Term Exposure To Cigarettes Figure 2-5 Long-Term Exposure To Cigarettes