• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 32 subscribers
  • Views 891 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

HDC Humidity Reading low

Richard Robinson
Intellectual 730 points
Other Parts Discussed in Thread: HDC1000

Hi,

I have a design using the HDC1000. The chip is located right on the edge of the board. But admittedly not as well thermally isolated as it could be. As a consequence the temperature reading is about 10F greater than ambient due to the temperature of the PCB. This isn't really a problem the sensor is only required to give an approximation inside the equipment. The problem that I have is that it is reporting 7% RH against 25% RH from a calibrated sensor. The difference from the ambient temperature does not account for such a large discrepancy. Is it possible that the   device has been damaged during re-flow?     

Thanks.

  • 0
    TI__Genius 14825 points
    Our apologies for the delay in your response. This is a holiday weekend in the United States; we will have the appropriate engineer review your question when we return to work next week. Thank you for your patience.
  • 0 in reply to Jason Bridgmon
    TI__Intellectual 1960 points
    Dear RKRobinson

    The difference in temperature can explain the difference in the humidity.
    HDC1000 read the relative humidity. Relative humidity is strictly related to the temperature, as rules of thumb with the same amount of water vapor in the ambient an increase of 1deC is equivalent to a -4%RH vale in the humidity.

    If the HDC1000 temperature sensor read a different temperature value vs. the ambient temperature the difference in the humidity is expected.

    The suggestion is to isolate (with trench in the PCB) the sensor from the heat source in the PCB

    Bes Regards
    Massimo