The CS615 Water Content Reflectometer measures the volumetric water content of porous media using time-domain measurement methods. The reflectometer connects directly to the single-ended analog input of a Campbell Scientific CR510, CR10(X), or CR23X, or to the pulse count channel of a CR510, CR10(X), 21X, CR23X, or CR7 datalogger. The data logger period or frequency output can be converted to volumetric water content using calibration values.