Pretoria Radiocarbon Dates I

Abstract
In 1969 radiocarbon dating facilities were established at the National Physical Research Laboratory of the C.S.I.R. in Pretoria (25° 43′ S Lat, 28° 21′ E Long; alt 1500 m). The counters are situated in an underground room built of selected concrete and covered by ca. 12 m earth. In this room, the nucleonic component of cosmic radiation is practically absent and the meson flux is reduced by a factor of 3.5 as compared to the surface at sea level in Groningen, Netherlands. A neutron monitor which registers 30 cpm on the surface, counts ca. 0.1 cpm in the underground room.