CALIBRATION OF THE CAPACITIVE SOIL MOISTURE SENSOR

Dear dfrobot-Team,
The capacitive soil moisture sensor works perfectly fine and as always the manual is well documented and nice to follow:
https://wiki.dfrobot.com/Capacitive_Soi ... KU_SEN0193
I am wondering if there is some 'sophisticated' way to calibrate the sensor besides this rough grouping:
The capacitive soil moisture sensor works perfectly fine and as always the manual is well documented and nice to follow:
https://wiki.dfrobot.com/Capacitive_Soi ... KU_SEN0193
I am wondering if there is some 'sophisticated' way to calibrate the sensor besides this rough grouping: