Delmhorst GB-1 - Gypsum Block 6' Lead
The blocks are made of gypsum, cast around two concentric, stainless steel electrodes. They are manufactured under controlled conditions to obtain a maximum degree of uniformity and fast response to soil moisture changes. The GB-1 measures 7/8” dia. x 1 1/8” in height. It is the most widely used sensing unit, easy to install and especially suited for extensive sampling of soil at various depths.