Patent Number: 043137920
Section: claims

1. In combination with a radioactive environment having a plurality of radiation measuring zones within which sensor devices are mounted for monitoring radiation activity, a traveling probe, means mounted in each of the sensor devices for guiding said probe along paths of movement through each of the zones, and means connected to the probe for calibrating the sensor devices in response to travel of the probe through said zones, the improvement residing in said sensor devices being of the gamma radiation measuring type and said probe including heat sink means for establishing a reference temperature region to which heat flows, elongated heat generating means extending from the heat sink means along each of the paths of movement for establishing a heat flow path to the heat sink means, means for thermally isolating the heat generating means from the sensor device, thermocouple junction means for sensing differential temperatures between the heat sink means and the heat generating means, signal conducting means connected to the junction means for transmitting signals therefrom to the calibrating means externally of the radioactive environment to adjust calculation of power from signal outputs of the sensor devices, and an elongated flexible sheath thermally connected to the heat sink means and protectively enclosing the signal conducting means. 2. The combination of claim 1 wherein each of said sensor devices includes a gamma radiation absorbing body having axially spaced thermal resistance portions therein, multiple junction thermocouple cables, and a support element operatively positioning said cables on the body, said support element having a bore extending therethrough forming one of the paths of movement for the probe. 3. The combination of claim 2 including propelling means mounted on the sheath for displacement of the probe along the paths of movement. 4. The combination of claim 2 wherein the heat sink means comprises a thermally conductive centering spring connected to the sheath and in sliding contact with the support element within the bore. 5. The combination of claim 4 wherein said thermal isolating means comprises a shield extending from the heat sink means in enclosing relation to the heat generating means. 6. The combination of claim 5 wherein said thermal isolating means further includes a low thermally conductive gas space between the shield and the heat generating means.