SNAA344 October   2020 HDC2080

 

  1.   Trademarks
  2. 1Introduction
  3. 2Temperature Accuracy Compensation
    1. 2.1 Linear or Polynomial Regression
  4. 3Relative Humidity Correction
  5. 4Response Compensation
    1. 4.1 Symptoms of Slow Thermal Response
    2. 4.2 Simulating Thermal Response Compensation
    3. 4.3 Realistic Thermal Response Compensation
  6. 5Summary
  7. 6References

Summary

Here three kinds of compensation techniques for temperature and humidity sensors were presented. Section 2 briefly discussed temperature compensation for ambient temperature systems with steady-state temperature error, which manifests as a difference in accuracy between the system and an external reference after settling time. Similarly, Section 3 discusses how to compensate for steady-state system humidity error, which will also manifest in temperature and humidity sensing systems that have poor temperature accuracy. Both of these are typically due to either poor airflow or sensor proximity to heat generating components. These methods require only system characterization across the desired operating range, and some basic mathematical compensation to be performed.

Section 4 examines a correction technique for transient errors in temperature and humidity sensing systems. This kind of compensation is typically needed in systems with large thermal time constants, and is most useful in applications where transient temperature conditions are regularly expected, and the temperature/humidity sensor is a critical part of the control loop, such as in HVAC systems. The ideal implementation and a practical implementation accounting for noise are both presented here. Threshold and averaging values can be selected to tune performance of a system while providing significant improvements to slow responding temperature systems.