HDC3022: What is the life for accuracy for 2-3 years of operation.

Hi Manthan,

What are the temp and humidity conditions that the HDC3022 is being operated and stored at? What RH measurement and error are you seeing on the HDC3022? 

The HDC302X has a long-term drift spec of 0.19%RH/yr. However, prolonged exposure to high humidity can cause the sensor reading to shift as the sensor absorbs excess moisture. The IP67 filter should protect the sensor polymer from external liquid water and it will take longer to fully saturate at high humidity, but left long enough at 100%RH and the filter will eventually reach 100%RH and sensor will absorb moisture. To recover or reduce the error, you can perform a bake + rehydration; see the suggested procedure below. 

1. Baking: 100C, at less than 5%RH, for 5-10 hours
2. Rehydration: 25C and 50%RH for 5 days

You can also use the built-in heater to bake out moisture and correct a positive RH error. You may need to experiment to see how much offset can be removed and which heater conditions work best in your application. The settling time and peak temperature attainable by using the integrated heater will be largely dependent on the board layout and the operating voltage of the device. See datasheet section 7.5.7.7-8 on how to enable and configure the heater. 

Best regards,

Sakeenah Khan

Hi Sakeenah,

What are the temp and humidity conditions that the HDC3022 is being operated and stored at? What RH measurement and error are you seeing on the HDC3022? 

The storage temperature and humidity condition will be approximate:- 24°C  to 30°C and %RH around 50%RH to 70%RH.

We are getting error around 3.0 to 4.0 %RH @50%RH.

We cant turn on heater in running application as those are in logging mode. (We can try on it but not on final application at user side).

We are currently using fresh sensor to check 1st, but we are not getting accuracy as mentioned in datasheet around 0.5%RH to 2.0%RH.

Also as we go high we get 100 RH at 81%RH on master. 

What could be the reason and how can we solve, do we have to use heater even for our fresh new sensor, we have already procure 500Qty sensor and we are about to buy 700 more. (For our multiple product range). we also has battery operated logger in which we cant use heater mode.

for continuous power on product we can think on it but when and how to use this  mode is bit challenging.

Hi Manthan,

Thanks for the information. I have a few more questions before making another suggestion. 

What equipment and procedure are you using to measure the HDC3022 accuracy? The devices showing 3-4%RH error, are these fresh sensors or sensors that have been used in their application already?

Are these devices in a condensing environment, or are there any liquid water drops present? 

Also do you mind sharing the lot # or date code associated with the order? (This info should be labeled on the original box/bag)

Best regards,

Sakeenah Khan

What equipment and procedure are you using to measure the HDC3022 accuracy? The devices showing 3-4%RH error, are these fresh sensors or sensors that have been used in their application already?

We are having Stability chamber and as mentioned, we are having Rotronic Make Hygroclip sensor which has +/-0.2°C and +/-0.8%RH accuracy.

Are these devices in a condensing environment, or are there any liquid water drops present? 

No we still not have kept for condensing environment testing yet, we are initially trying to check normal environment accuracy testing, no their are not water drop present on sensing area.

Also do you mind sharing the lot # or date code associated with the order? (This info should be labeled on the original box/bag)

we have purchase those from mouser, check below details for your reference.

Batch No:- 24TLBX

Date Code:- 05D07

Let me know your comments..

Hi Sakeenah,

i still not have check above points which you have mentioned.

I have one query and doubt, in my application i have used 3.3VDC as supply voltage for sensor, but in datasheet although the supply range is 1.62- 5.5VDC the testing parameter is given on 1.8VDC so do i have to use 1.8VDC for sensor to achieve given standard RH accuracy?

Regards

Dear Sakeenah,

Thanks for your comments.

Today we have done below test on two HDC3022 sensor which we have tested and having 3.0 to 7.0%RH error, 

Test Condition in chamber :- 70°C and 15%RH

Kept devices / Sensor for half an hours in above stable condition, after this test the error in RH was reduce to 3.0 %RH to 4.0%RH for below condition

1. 20%RH @ 25.0°C

2. 30%RH @ 25.0°C

3. 40%RH @ 25.0°C

4. 50%RH @ 25.0°C

5. 60%RH @ 25.0°C

6. 70%RH @ 25.0°C

7. 80%RH @ 25.0°C

8. 90%RH @ 25.0°C

It recovers a bit, but will it stay as it is or will revert back to its old error state?

Tomorrow we will going to keep same those 2sensor in same condition 70°C and 15%RH for more 1 to 2 hours and will check its result again.

What do you think or what is your comments on this?

As those 2 sensor are fresh but still we found this error condition.

Regards

Sanjay Sutar (Manthan colleague)

Hi Sanjay,

3-7%RH error on fresh devices sounds too high, especially for fresh devices. Fresh sensors that have not been used or exposed to harsh humidity/temperature/contaminants should be within datasheet spec and should not require any bake/heating.

To clarify the test procedure, you kept some devices in a chamber at +70C/15%RH for some time, then removed them from the chamber, swept humidity up from 20->90%RH (at 25C) and measured humidity accuracy. Can you please share the data log? Did you measure both an upsweep and a downsweep? The RH Accuracy spec excludes hysteresis, so the best practice would be to perform a humidity upsweep and downsweep to measure the average RH error and hysteresis. Also, how long did you wait at each humidity setpoint after allowing the humidity to "settle"? 

You mentioned these 2 sensors are fresh devices. Meaning they have not been exposed to harsh (high) humidity/temperature conditions for extended time, yes? Can you please share the storage and assembly process? 

• How were the devices stored?
  • Was pink foam used to store them?
• What materials and methods are used during assembly?
  • Is there any possibility of chemical exposure on these devices? Examples of potential contaminant sources: cleaning agents, flux, aerosol duster, heat gun, outgassing from epoxies/glues/adhesives
  • The PTFE filter can block particles up to 100nm, which helps against dust and liquid water, but the device can still be susceptible to contamination
• The HDC302x Silicon Users Guide details the proper storage and handling guidelines
• Can you please take a picture of the TI box label? I think the #'s you gave me before were from Mouser's tracking, not TI.

Best regards,

Sakeenah Khan

Hi Sakeenah,

I have attached some images of our devices and it structure, let me know it has any mechanical issue which might cause this RH error issue.

HDC3022 Sensor with Product.pdf

Also i have attached report of different sensor configuration with HDC3022.

Let me know your comments, Other details i will share once i received.

Regards

Sanjay Sutar

Hi Sakeenah,

Please find report.HDC3022_Chamber Test_020924.xls.xlsx

Regards

Sanjay Sutar

Hi Sanjay,

Thanks for sharing your data log. I calculated the average RH error at each setpoint and agree it seems too high. 

Were these devices exposed to harsh conditions (high humidity/temperature) for an extended period of time? What is the storage condition? If you are able to answer the troubleshooting questions from my last message that will also help. 

How may modules did you test? Do you observe the same amount of RH error based on the type of board (e.g. do all the Duct Mount Sensors show comparatively better performance) or is the device performance pretty random? 

Best regards,

Sakeenah Khan

Hi Sakeenah,

I did not have check with quantity, As all above model sensor module are from same lot and procured through mouser but sorry i could not able to get the TI label, as those were misplace after assembly (EMS).

Do MSL level effect to sensor performance, it was mentioned as MSL 1, which is storage period unlimited and can be store in <85%RH (In manufacturer package).

Above question

1. Also, how long did you wait at each humidity setpoint after allowing the humidity to "settle"? 

We took reading 15 minutes after stabilizing the chambers in particular chamber, Only at high RH above 85%RH our chamber is not much stable it is having +/-1.5%RH swing.

2. Can you please share the storage and assembly process?

Once we receive sensor module we keep those in storage with the environmental condition 25°C to 35°C., Humidity 45%RH to 75%RH.

After product assembly (EMS) we keep assembled PCB and then product in range of 25°C to 35°C and RH 50%RH to 75%RH.

all product fitting and assembly with ABS enclosure, Teflon filter within ABS CAP

3. How were the devices stored?

• Was pink foam used to store them?

No We do not keep device in pink foam, We keep sensor IC in ESD bags and assembled finish product in Corrugated box.

4. What materials and methods are used during assembly?

• Is there any possibility of chemical exposure on these devices? Examples of potential contaminant sources: cleaning agents, flux, aerosol duster, heat gun, outgassing from epoxies/glues/adhesives

In PCB assembly and at product we have strictly mentioned guideline which are given in datasheet, we do not use lacquer to clear board, instead we use no clean pest cookson make.

• The PTFE filter can block particles up to 100nm, which helps against dust and liquid water, but the device can still be susceptible to contamination

Except battery operated logger all other product we are having PTFE filter.

5. The HDC302x Silicon Users Guide details the proper storage and handling guidelines

We referred this for our 1st R&D lot, product still to be release for production so it will be added in SOP.

6. Can you please take a picture of the TI box label? I think the #'s you gave me before were from Mouser's tracking, not TI.

Sorry but as i mentioned i did not found TI label i could only manage to get mouser tracking details as it was mentioned in our IQC system.

Now we have order new lot of TI HDC3022 sensor, we will now try same above testing on this those new sensors. This we might give good result it will also clear any batch related issue.

Check below new lot details.

Still further information required let me know.

Regard

Sanjay Sutar

Hi Sanjay,

Thank you for the extra information.

Can you please read the NIST registers for the problem devices (one per batch)? Please see datasheet section 7.5.7.9 for the instructions. 

Can you please inform me your company name? Do you know which FAE (field applications engineer) is assigned to your company? 

Also, if you can share your email, I would like to take this offline to loop in additional team members on this issue. 

Best regards,

Sakeenah Khan

Dear Sakeenah,

Thanks for your reply and further interest to resolving our query.

Company Name:- enviro Technologies

Location : India (Mumbai) 

Can you please read the NIST registers for the problem devices (one per batch)? Please see datasheet section 7.5.7.9 for the instructions

I will check and revert  back to you.

FAE :-  Initially we were using Sensirion Sensor , due to RH issue we shifted to TI HDC series model on the basis of its datasheet details Accuracy and 1st trial sample test (which given us good accuracy at Lower RH). So we did not approach to any FAE , also in our nearest location their is no FAE available, it is nearest available at Pune (Maharashtra / India).

 Email ID:- Sanjay.s@enviroworld.in

Regards

Sanjay Sutar