its own sheath requiring a separate weld in many such applications the relatively large number of welds could not be accommodated at the flange the number of conductor pairs 28 within each sheath and the number of sheaths utilized can be adjusted according to application and design parameters for example a single sheath may be able to contain sufficient conductor pairs 28 to provide temperature sensing capability at all of the desired locations or the temperature sensing junctions can be divided between additional sheaths also the use of additional sheaths that each contain one or more conductor pairs 28 permits those sheaths to be bent curled arced or otherwise formed to sense temperatures at a variety of other locations within the vessel 100 as illustrated best in fig8 the one or more sheaths 22 preferably include a relief section 114 disposed within containment chamber 60 to facilitate flexing of the sheath due to for example thermal expansion the relief section 114 of each sheath may comprise an arcuate section 116 that provides the sheath with sufficient flexibility depending on the application and type of vessel 100 utilized in the application the attachment of thermocouple system 20 to pressure vessel 100 may vary however one exemplary embodiment utilizes a neck 118 fastened to vessel 100 by for example a weldment neck 118 is deployed around an opening 120 formed through the outer wall 122 of vessel 100 a flange 124 is connected to an upper end of neck 118 to facilitate mounting of thermocouple system 20 flange 124 typically is welded to neck 118.