More than 1 temperature sensor on 1 input - series parallel
Any controller that reads resistive inputs.
There is only 1 input, but the end user wants more than 1 sensor. (Note: the reading will be averaged)
4 resistive sensors are required.
Depending on scenario, 2 sensors may have to be fitted adjacent to each other, or fit 2 sensors into 1 sensor housing to achieve the correct number of zones to be monitored.
For wiring follow the drawing below: