Ando's AQ7700 oscilloscope uses electro-optic sampling technology for electric signal measurement. It is capable of ultrahigh input impedance measurement, simplifying gigahertz-zone frequency calculations. The AQ7700 is suitable for measuring large printed circuit boards that tend to be influenced by ground position and low-driving circuits with low disturbance under high input impedance. The device increases performance and usability by eliminating the need for ground contact for electric circuit measurement. The probe head and detection parts are electrically isolated, and the probe is unaffected by electrostatic discharge.