1. A method for nondestructively determining the dimensional changes in an object as a function of temperature over a desired temperature range, comprising: a) scanning a single cross-section of said object with penetrating radiation along a plurality of paths; b) sensing the temperature of the object as the object is being scanned and generating temperature signals representative of the temperature of the cross-section of the object; c) generating electrical signals representative of the radiation attenuation along each of the plurality of paths through the cross-section of the object; d) converting the electrical signals representative of the attenuated penetrating radiation signals into signals representative of the density-length of the object along each of the plurality of paths; e) processing the density-length signals to determine, by use of a computer model of the object to be examined, dimensional measurements of a cross-section of the object; f) processing the temperature signals to generate a temperature which corresponds with each determined dimensional measurement; g) allowing the object to increase and/or decrease in temperature; and h) periodically repeating steps a) through g) at different temperatures whereby a series of correlated dimensional and temperature measurements are taken of the same cross-section over the desired temperature range.