The Watermark 200SS (https://www.irrometer.com/sensors.html#wm) measures soil water tension in centibars (cb) at the installation depth chosen by the user. Low soil water tension corresponds to wet soil whereas high soil water tension corresponds to dry soil. For installation, the manufacturer recommends using a 7/8” soil probe with a slide hammer. An earth auger may be used for soils with compaction/hardpans. An installation video can be viewed at the following link (https://www.youtube.com/watch?v=GnpsO97a9lE).