I know this can be done because we use this very simple device daily. What I am trying to do is to take the exact same sensor used in this device and build it into a digital panel that will allow the combination of data from several other sensors to be read all together.
The company would not give me the formula they use and their datasheet was rather limited. i.e. 25 degree C requires no correction.
I found a formula, which I posted above that would convert. While this is similar to a thermistor sensor it does look a little different. When reading Total Dissolved Solids it is basically sending a pulse through the medium. The delay of these pulses will tell you the amount of solids. It is also a function of how conductive the medium is.
In this particular case I want to find out how much salt is in water. If I submerge the sensor in pure water I would receive a reading of 0 TDS. Saltwater has an average concentration of 35k TDS (Different areas of the world can have higher or lower)
So what the Arduino needs to do is to send a pulse and then read the pulse (I am assuming on the PWM TX RX pins)
It will then take this and process the delay according to a math formula (The one above)
Temperature does effect these readings. (I do believe it is a property of thermal dynamics)
So temperature and salinity need to have an arbitrary baseline set for the calculation. I know the temperature baseline is 25 degrees C, I am waiting on the company that manufactures the sensor to tell me what the baseline for the salinity is.
In the meantime though, I am trying to figure out the code behind the following:
Sending/receiving the pulse from the Arduino.
Calculating the TDS/EC
I am open for suggestions and hints.
I do appreciate everyones time and abilities (Would happily by those that help a drink)
I have been googling and will continue to do so, but have been hitting a lot of walls, that is why I brought it to this community, which is know for being helpful.
If you need to know something else just ask.