Theodor Wulf is best known as a German physicist who gained recognition for his work in the field of high-altitude physics and for his experiments related to cosmic rays. He is perhaps most famous for his 1912 experiments which demonstrated that radiation intensity changes with altitude, providing early evidence for the existence of cosmic rays. Wulf is also associated with the "Wulf radiation" effect, which refers to the variations in radiation experienced at different altitudes.
Articles by others on the same topic
Theodor Wulf developed a transportable electrometer for measuring atmospheric ionization. His design used fine fibres in place of delicate metal leaves, making outdoor measurements easier to calibrate. Comparisons at different heights, including the Eiffel Tower, tested whether radiation from the ground explained the ionization.[ref]
The method infers ion production from loss of stored electric charge. Leakage and instrument stability must therefore be controlled before a change in discharge rate is interpreted as a change in penetrating radiation.