INSPECT- Ultra Small NDT Probe - SiPS - Inesc-ID

INSPECT- Ultra Small NDT Probe
“INSPECT - Integrated Nano Sensor Probes and Electronics for Eddy Currents Testing”
Project FCT: PTDC/EEI-PRO/3219/2012
Authors: João Graça, Diogo Caetano, José Germano, Jorge Fernandes, Moisés Piedade.
INESC-ID, August 2015
Following the successful development of a CMOS Application Specific Integrated Circuit, ASIC, for
INSPECT, by INEC-ID, a new highly integrated type of probe for NDT eddy current, based on four Magnetoresistive sensor arrays (produced by INEC-MN) was developed. To achieve this goal, a very compact printed
circuit board was designed specifically to incorporate four ASICs and four sensor arrays. An additional
printed circuit board is available and connection cable to adapt the new probe to the main signal
acquisition and processing system.
The new probe is comprised of the following characteristics:
• Very small in size, 26.6 mm by 20 mm.
• Ultra low noise voltage regulator and a low noise voltage reference.
• 128 highly sensitive magneto-resistive sensors.
• Four high speed unity gain buffers with high output current to interface with the ASICs outputs.
• Current line for magnetic driving of superficial defects and pads to connect coils used for buried
defects detection.
The printed circuit board to test the new probes is comprised of the following:
• DIP switches to set the ASICs gains.
• Two buttons, to reset (RESET) and to select the next sensor (NSYNC).
• SMA connectors for each ASIC output, and current line and coils inputs.
Fig1a. Miniature probe (front).
Fig1b. Miniature probe (back)
Fig2. Interface circuit for the probe.