Medical Definition of adhesive. 1: an adhesive substance; especially : a substance (as glue, starch, paste, or mucilage) that bonds two materials together by adhering to the surface of each.
The sensors physically measure the tire pressure in each tire and report it to the vehicle's instrument cluster or a corresponding monitor. Some units also measure and alert temperatures of the tire as well. These systems can identify under-inflation in any combination, be it one tire or all, simultaneously.
A deviation from the recommended inflation pressure of your tires will cause the Tire Pressure Monitoring System (TPMS) on your car to be activated. Most TPMS measure your tires when they become significantly underinflated, and not overinflated.