Fig. 5: Development and integration of a smart wireless readout circuitry to the differential SRR-based NDI system.

a Bluetooth-enabled smart readout circuitry connected to the WRC-coated differential NDI system, and the block diagram of the readout circuitry connected to the Android application via Bluetooth. b Amplitude monitoring mechanism at three discrete frequency points along with the amplitude look-up table to determine the erosion status of the WRC-coated differential SRR system. RF radio frequency.