1. The conductor should be grounded (or charged itself), and the human body can see that the conductor is grounded through a large capacitor, so the person directly holds the conductor is equivalent to grounding;
2. If the contact area between the conductor and the touch screen is large enough, it depends on the size of the touch screen electrode (Pitch) and the algorithm of the touch screen.
Generally, the Pitch of TP is about 5mm, so the minimum contact area should not be less than 5mm, otherwise the touch screen can read the touch of an object, but it is difficult to calculate the accurate touch position (the touch IC calculation of the touch position requires several touch electrodes near the touch position to have a relatively linear signal strength distribution). At this time, the IC will not necessarily report the event as a trigger to the system.