HDC2022: Calibration on HDC2022

Dear Nan - 

A1. The HDC devices are calibrated or "trimmed" at the factory and tested multiple times before being shipped. The HDC2 device specifically has a typical offset due to aging of 0.25%/year. This is usually a positive offset and could be calibrated out if provisions were already made to apply this in the field, as described in another post, or could be returned and offset applied (i.e. for a yearly calibration, just like lab/test equipment is handled) - totally up to system integrator. Careful characterization of multiple boards with same layout while using the heater can get you decent results - at least back to within DS spec or better. I personally like to run this algo on all the parts I come into contact with, as it is quick and easy to use and the look up table values can also be done in Fahrenheit for even more fine tuning of the exact heat rise temperature needed to get the correct value for a given layout with these parts.

Cutouts like these have proven to yield best results.

A2. As these types of sensors are open to the environment, they do have specific handling procedures as a result and in the cases where the %RH sensor measurement is offset, the units could be considered to be out of spec and therefore need an offset calibration applied. The HDC2022 has offset registers, but they are volatile, so any offset value that could be written would need to be done after a POR or SW reset. The HDC3 parts have a non-volatile offset register, just FYI. 

A3. I am not sure I understand this question - would you please restate? 

Hi josh,

    Q3: What is the maximum offset on HDC2022 humidity measurement? Could it be reasonable the offset is 60%RH?

YOURS

NAN

HI Josh,

     Thanks for your confirm.

YOURS

NAN