Fig. 7From: First field application of temperature sensor modules for groundwater flow detection near borehole heat exchangerMeasured and simulated TSM temperatures at 82 m depth. The left and right columns show the inner and outer ring temperatures, respectively. They are shown both as a standard plot (a–d) and as a polar plot (e, f). a, b show the temperatures before BHE operation, c, d the steady-state temperatures during BHE operation. Black squares represent the measured data; solid and dashed black lines represent the simulated temperatures with and without groundwater flow, respectively. The red square marks the position of the first sensorBack to article page