A corrosion detection apparatus for permanently and integrally monitoring a state of corrosion of a component is provided. One or more endoluminal instruments may be advanced per-orally into the previously formed failed pouch where a number of different procedures can be performed. The control signal includes alternating first periods and second periods, where the first periods and the second periods correspond to the ON-periods and the OFF-periods of the input PWM signal, respectively. Further, a relative phase between at least one third electro-magnetic radiation electro-magnetic radiation being returned from the sample and at least one fourth electro-magnetic radiation returned from a reference can be obtained to determine a relative depth location of the portion. The conforming interface layer over the conducting polymer plug is mated with the corresponding metal bump. The tubing assembly can provide a flow rate or volume capacity that is generally equal to or greater than that achieved with a comparable prior art tube while operating at higher pressures than that possible using the prior art tube.