Though the character of the signature is missing the discrete points yield a more visual interpretation of the spatial extent of the radiometric highs and lows. As with any survey, the greater the sample density the better the interpretation. R adiometrics is a first wave culling tool for reconnaissance geochemical surveys. It should be used to delineate anomalies that can be tested for the presence of hydrocarbons using other surface geochemical techniques. A gamma ray spectrometer is a device that separates gamma radiation into two or more energy components.
Spectrometers require a detector and a device to analyze the signal.
The detector, normally a sodium iodide crystal, absorbs the gamma radiation and converts it to a light flash or scintillation. The light is received by a photomultiplier tube which converts the light flash to a voltage proportional to the intensity of the light flash. The counting device then separates the voltage into a number of magnitude dependent classes which represents the energy spectrum of the incident gamma rays. M ost of the useful gamma emissions, for petroleum exploration, are located in the low energy range of the spectrum below Potassium 40. A cquistion of radiometric data does require a knowledge of the variables that can affect the gamma ray signal.