The turbidity sensing principle is that an infrared light source passed through the water and received by the photoelectric crystal which transferred thr light into a current in the other end.
This current can be converted to the corresponding turbidity standard based on the relationship between optical power and water turbidity.
Conductivity is the ability of an object to conduct current. The conductivity measurement principle is to put two parallel plates into the solution to be tested.
Apply a certain potential (usually a sinusoidal voltage) across the plates and measure the current flowing between the plates.