HDC2022: How to estimate the error of HDC2022 for 1 year?

veera venkateswara rao pusala

Part Number: HDC2022

Hi,

can anyone answer below questions?

Q1) I am going to use HDC2022 in 80% RH @ 10C, and trying to estimate the error for one year as below, please confirm? my application requires the error should be less than 5% RH.

HDC2022 worst case error = 2%(accuracy for <80% RH) + 1%(hysteresis) + 0.25% (drift for 1 year) =3.25% RH

Q2) I read the long term drift of HDC2022 is 0.25% RH positive side ( +0.25 %RH /year) from one of the post, is that true?

Q3) The datasheet has typical spec i.e. LTD, Hysteresis, accuracy etc., what are the approximate maximum numbers?

Q4) Is there any way to measure the LTD for my application (test fixture) by stressing the sensor thermally?

over 1 year ago

0 Rooshi Nagar over 1 year ago

TI__Prodigy 480 points

Hi Veera,

1. Yes, this would be the worst case error for the application.

2. It can be +/- .25% RH/year, as listed in the datasheet.

3. Maximum LTD would depend on the way that the device is used - putting it in harsh situations would hurt the LTD at a much faster rate. There is a humidity max accuracy of +/-3% and temperature max accuracy of +/-.4C.

4. You could look into using the Arrhenius equation in order to evaluate the device at different stressing conditions.

Best regards,

Rooshi

0 veera venkateswara rao pusala over 1 year ago in reply to Rooshi Nagar

Intellectual 280 points

Thanks Rooshi.

Regarding question 4, do you have any supporting document or study paper like 'X' LTD for 'certain stressing conditions", so we can derive expected drift number. we just have water misting or spray for rise environment humidity (no chemicals).

I am going to use CM10 - chilled mirror hygrometer (Dew + Temp) for calibrating the HDC2022 especially LTD, do you think it is good option? if not please propose good precise reference sensor with high repeatability?

The reference sensor (CM10) has some uncertainty of +/-1.8 %RH, what is the uncertainty for HDC2022?

Regarding Heater usage, I found one document for HDC3. I hope it is same for HDC2xxx. For getting right offset value, how long or what temp. we need to rise the die temperature?

https://www.ti.com/lit/ug/snau265b/snau265b.pdf#page=15&zoom=100,0,70

Regards,

Veera Pusala

0 Rooshi Nagar over 1 year ago in reply to veera venkateswara rao pusala

TI__Prodigy 480 points

Hi Veera,

1. Please take a look at this document: https://www.ti.com/lit/an/snaa353a/snaa353a.pdf?ts=1682622566990. Let me know if that helps. For a list of chemicals that can impact drift, take a look at this User's Guide: https://www.ti.com/lit/ug/snau250/snau250.pdf?ts=1682622961335&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FHDC2022%253FkeyMatch%253DHDC2022%2526tisearch%253Dsearch-everything%2526usecase%253DGPN-ALT.

2. I am not familiar with the CM10, we use the Rotronic HF532 so I would propose that device; however, I'm sure the CM10 will work.

3. Looking at the datasheet for the CM10, I do not see where it mentions the uncertainty. The uncertainty for the HDC2022 is +/-2C typical accuracy and +/-3C max accuracy.

4. Information regarding the heater for the HDC2022 can be found in the User's Guide I linked at the beginning of this reply. For getting the right offset value, please take a look at this E2E post from earlier: https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/1221045/hdc2010-applying-offset-error-correction-mentioned-in-hdc3-silicon-users-guide.

Best regards,

Rooshi

0 veera venkateswara rao pusala over 1 year ago in reply to Rooshi Nagar

Intellectual 280 points

Hi Rooshi,

I have gone through the spec. of Rotronic HF532, It looks the drift of the device is ~1 % RH. how did you verify HDC2022 drift by using HF532 probe? did you stress the HDC2022 thermally and arrive some number as per "Arrhenius equation"? can you please explain how did you do that measurement? please share if you have any document?

I am trying to estimate the HDC2022 total error for my environment test conditions.

Regards,

Veera Pusala

0 Josh Wyatt over 1 year ago in reply to veera venkateswara rao pusala

TI__Guru* 91146 points

Veera -

Just answered your email - closing this post.

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HDC2022: How to estimate the error of HDC2022 for 1 year?