Gravity: Analog TDS Sensor Sample Code
Account cancelled 2021-12-24 05:26:17 1101 Views1 Replies Hello
I have a question about the Gravity TDS sensor.
In the library , the formula for calculating TDS looks like this:
TDS=(133.42*voltage* voltage * voltage -255.86* voltage * voltage +857.39* voltage)/(1.0+0.02(temp-25))*TDSFactor
And in the example page of the site https://wiki.dfrobot.com/Gravity__Analo ... 4#target_3
compensationVoltage=voltage/(1.0+0.02*(temp-25))
TDS=(133.42* compensationVoltage * compensationVoltage * compensationVoltage -255.86* compensationVoltage * compensationVoltage +857.39* compensationVoltage)*TDSFactor
These are calculations in different ways, which option is correct?
I have a question about the Gravity TDS sensor.
In the library , the formula for calculating TDS looks like this:
TDS=(133.42*voltage* voltage * voltage -255.86* voltage * voltage +857.39* voltage)/(1.0+0.02(temp-25))*TDSFactor
And in the example page of the site https://wiki.dfrobot.com/Gravity__Analo ... 4#target_3
compensationVoltage=voltage/(1.0+0.02*(temp-25))
TDS=(133.42* compensationVoltage * compensationVoltage * compensationVoltage -255.86* compensationVoltage * compensationVoltage +857.39* compensationVoltage)*TDSFactor
These are calculations in different ways, which option is correct?
2022-05-09 19:05:21 
Youyou
The first formula is to convert the voltage value to the corresponding TDS value.The second formula performs temperature compensation, because the temperature has an influence on the TDS value, and temperature compensation can try to eliminate this influence.Both formulas are correct and required.
Youyou 
