By szelam0525
#29028
So, I purchased an Analog Dissolved Oxygen Sensor / Meter Kit For Arduino (Model: SKU:SEN0237-A) and have tried to do the calibration and actual reading according to the Wiki tutorial. However, the sensor returned the same values (around 8.3mg/L) in whatever solution I put it in. I tried to test it with 3 water samples with different DO values (as measured by the DO meter in lab) i.e. 1.4mg/L, 7mg/L, and 9.5mg/L, but it returned the same values no matter what.

Please help and thanks in advance!!!
By nana.wang
#29031
Hi, thanks for your support.
Please offer more details related to environment, such as temperature. Images and videos will help us find the key point.
This problem has passed to engineers related, we will feedback to you as soon as possible.
By nana.wang
#29032
Checked with the tech support, please check and pour 0.5 mol/L NaOH solution to the membrane cap before use, calibration and test.
The images below are for your reference.
Attachments
rosultion operation.png
wiki notes.png