This insertion auger facilitates the simple and gentle installation of type 120, 151 and 152 tensiometers, suction probes with ceramic cup as well as the soil profile temperature probe. The insertion auger excavates a drilling core, in order to compress the surrounding soil as little as possible, when inserting the tensiometer into the soil. Thus, falsifying influences on the measured values caused by the installation are minimal. The adapted, conical shape of the drill allows for optimal contact between the ceramic and the soil, enabling a good connection to the pore system. Using the insertion auger, the suitability of the measuring site for tensiometer measurements can be estimated directly before installation. During drilling, obstacles within the soil horizons can be detected, thus preventing damage to the tensiometer. The drilling core exposes information on the soil at the measuring site.