One aspect of the present disclosure discloses a probe, including a probe body having a center axis defining a proximal end and a distal end and including an aperture in the distal end; a window affixed in the aperture, wherein the window is substantially optically transparent; and a flange adjoining the proximal end of the probe body, the flange including a sealing surface and a sealing edge, wherein the flange separates an in-process portion of the probe from an ex-process portion of the probe, the in-process portion including at least the probe body, the sealing surface and the sealing edge, where at least the in-process portion of the probe consists essentially of an austenitic stainless steel material. Further aspects include a computer product configured to execute a method employing the probe.