In the CS107/108 temp sensors, how long is the actual sensor and where is it positioned inside the white tube?
The sensing element is a little thermistor bead positioned near the tip. The whole white section of the sensor is thermally conductive. It contains an aluminum tube, filled with thermal epoxy.
So, the tip is more sensitive to temperature, but you want the whole white section in the air, soil, or water you are measuring. For air temperature readings, the whole white section should be in a solar radiation shield.