smart board cable.There is also an ITO coating beneath the surface capacitive coating which is also typically required to use a linearized metal electrode around the screen to reduce the effect of the angular and side effects on the magnetic field. Sometimes there is also an ITO shield under the ITO coating to shield the noise. The surface capacitive touch screen should be calibrated at least once before use. The inductive capacitive touch screen can penetrate a thicker protective layer than the surface capacitive touch screen without correction. Inductive Capacitor etches different ITO modules on two ITO coatings. Factors such as the total impedance of each module, the impedance of the connection lines between the modules, and the parasitic capacitance generated by the intersection of the two layers of ITO modules need to be considered. In addition, in order to detect finger contact, the area of ??the ITO module should be smaller than the finger, and when a diamond pattern is used, the diagonal length is usually limited to between 4 and 6 mm.