Er, Houston, USA– www.slb.com, accessed 20 June 2021) had been applied to measure water and atmospheric pressures, respectively. The atmospheric pressure was subtracted from the water stress to estimate the water level at the position of the Diver probe in the river. A number of gauges of water flow had been performed making use of the electromagnetic current meter Flo-Mate 2000 (Marsh McBirney–Hach, Loveland, USA–www.hach.com, accessed 20 June 2021), permitting the elaboration of a rating curve, to convert the measured water level to water flow. This permitted a very good estimation of water level and water flow throughout the tracer tests together with the Roniciclib supplier target of checking for consistency of your waterflow during both tracer tests. The flowrate was continuous (0.247 m3 /s) all through the day, as outlined by the probes data. 2.3. Calibration of Fluorometers Tracer test information consisted of 1 min interval raw light intensity measurements at the emission wavelength of uranine [1]. This measurement was performed although a blue LED light was on, enabling for the excitation of uranine molecules. A correction of stray light was performed (as described by Poulain et al., 2017 [1]) before applying the calibration curve values to each dataset. This permitted us to acquire the final uranine concentration worth at each and every interval for each and every fluorometers. Internal clocks permitted for the synchronization of every fluorometer and using the injection time. Fluorometers had been precisely calibrated inside the lab before and following the test by the elaboration of a calibration curve. The curve hyperlinks the raw light intensity measurement on the device with all the uranine concentration. This permits the converting of raw fluorescence information to concentration in ppb. The calibration procedure was performed by the combination of manual and automatic calibrations (Figure two). Manual calibration was performed by AM251 Biological Activity exposing the fluorometer to a bath of a precise concentration, although automatic calibration was performed by exposing the fluorometer to a bath of gradually rising concentration making use of a precisely calibrated pump. The mixture of each processes allowed the deletion in the pump error when nonetheless obtaining a higher number of points on the calibration curve. The coefficient of determination R2 on the 2nd-order polynomial regression curve from the automatic calibration information typically reached more than 0.9999 with as much as 600 points. ThisHydrology 2021, 8, xx FOR PEER Overview Hydrology 2021, eight, FOR PEER REVIEW44 of 16 ofHydrology 2021, eight,applying aaprecisely calibrated pump. The combination of each processes allowed the deleusing precisely calibrated pump. The combination of each processes allowed the of 15 4 deletion with the pump error whilst nevertheless obtaining aahigh quantity of points on the calibration tion of the pump error while nevertheless obtaining high quantity of points on the calibration curve. The coefficient of determination R2 2of the 2nd-order polynomial regression curve curve. The coefficient of determination R with the 2nd-order polynomial regression curve of your automatic calibration information ordinarily reached more than 0.9999 with up to 600 points. on the automatic calibration information generally reached greater than 0.9999 with as much as 600 points. This assured the superior qualityof the calibration course of action, as a result allowing foran effective guaranteed the goodgoodqualitythethe calibration process, as a result enabling foran efficient This assured the high-quality of of calibration process, thus enabling for an efficient comparison in the data obtained for each fluorometer.