The reference temperature calibrator (RTC-156B) and plant growth chamber (HGC-154) enable high-accuracy calibrations of sap flow sensor measurement needles. Accurate calibrations are essential when quantifying sap flow and plant water content, but are also needed to ensure accurate performance of other temperature sensors (e.g. air temperature used in the UGent/FBW meteo-station). The fully controlled growth chamber is vital to ensure further temperature homogeneity during calibration work, to test temperature sensitivity of installed plant sensors, but also offers great opportunities to excel in sap flow research and research into (extreme) plant hydraulic functioning.