TDS writing data error

[mir161803]

I used the program code on your github, the program code was uploaded successfully, but there was a little oddity, when I read the serial monitor, the tds value was 17 ppm, but it happened when I hadn't dipped the probe into the water sample to test, is this the problem in the sensor tds or indeed the initial value of the sensor tds (not dipped in the liquid to be tested) is 17 ppm

[xZurdo]

The way in which TDS is caclulated is through EC. He first calculate the EC value and then makes the transformation (multypling by 0.5 or 0.6) to PPM. Probably the sensor is measuring the conductivity from the air, that is very little, but this very little value makes the sensor returns a value because the way to obtain PPM (TDS) is first getting EC. I think you don't have to worry about anything, it is just a very little measure of PPM it is like you are measuring a 0. There is no problem with that.

I hope I helped you

Regards.