I am trying to create a salinity measurement system with a range of 0-5000 ppm. However, when I use a voltage divider or potentiometer to measure various levels of ppm, the issue arises that they have limits to measuring within the 0-5000 ppm range. Here is an example for clarity: when I construct a voltage divider, it accurately measures within the range of 2000-3000 ppm but not accurately at 0-2000 and 3000-5000 ppm, which are the ranges I want to measure. How can I develop this type of system? I believe my calibration and the codes are fine; I have determined that this is the problem. Also, I am trying not to use commercially made products like TDS meters or any probes manufactured by companies; I am aiming to use fundamental materials.
We need more information. Like what voltages are where and what range of volts relate to the ppm's you need to measure? We don't need exact numbers just enough to get you in the ballpark.
The circuit is too complex to analyse from the picture, we need a schematic.
You will also need to give more details of your setup eg what is ORP and what is the nature of the "tube", and the solution (to be sure that silver counts as inert).
I see you are using a Uno. Can you post your code please.
I am measuring the salinity concentration in the range of 0-5000 ppm, such as by dissolving iodized salt in distilled water, and simply determining the ppm range.
Else your on your own. If this sounds harsh it's because the forum receives a fair number of requests for help from folks that don't want to give the details needed for members to help. Even if its a "I don't know but here is a link to what I'm trying to do"
