This study proposes coating impedance detector 3.0 (CID 3.0), an improved version of our previously developed CID 2.0. The new circuit design in CID 3.0 has lower power consumption because it has fewer components, and it affords better accuracy through the modification of the analog part of CID 2.0 and the use of oversampling. This approach successfully afforded CID 3.0 with higher measurement stability for evaluating a high-performance coating with impedance values exceeding 10 9 Ω. Furthermore, CID 3.0 could detect impedance decreases associated with coating delamination when the coating suffers an attack.