Measurable: Potassium-40 in rock, construction materials, fertilizers containing potassium, plants and animals.
Measurable: The gamma content in the progeny of the uranium (U-238, U-235) radioactive series.
Measurable: The gamma content in the progeny of the thorium-232 radioactive series (electrodes with thorium content, old gas mantles).
Measurable: Cesium-137, cobalt-60, radium-226 (old clocks, compasses etc.), limited Sr-90/Y-90.
Not measurable: Tritium, carbon-14, alpha emitters, (beta emitters).
The self-absorption of a material means that alpha emitters cannot be measured and that beta emitters can be measured only to a certain extent because the radiation simply doesn’t reach the Gamma-Scout. As specially prepared laboratory emitters, however, these emitters are measurable.