Abstract
These are data files and analysis code for "Design and initial test of a lower cost water sensor for nitrate". We provide one python script, "analysis.py", which we used to perform the analysis and generate the figures described in the manuscript. We provide the data files for the experiment. The following data files were collected with our prototype sensor, and are all described further in the manuscript:
temp_cal_initial.csv and temp_cal_rebuilt.csv, which provide the clean water temperature calibration data for the original and rebuilt sensor.
clean_water_initial.csv and clean_water_rebuilt.csv, which provide data from the nitrate calibration in distilled water for the original and rebuilt sensor.
dirty_water.csv, which is the calibration data in river water with added nitrate.
We also include a file doses.csv, which provides nitrate concentration data for the clean_water_initial.csv calibration file.
doses.csv has the following data columns:
time: describing the time nitrate solution was added
i: an iterator for how many times nitrate solution has been added per calibration run
vol: the amount of 274.6mg/L sodium nitrate solution added in mL
result: a diagnostic output from the dosing pump
nitrate_concentration: the resulting concentration of nitrate in the sample chamber after the addition in mg/L.
The other sensor data files have the following data columns:
dt_logged and dt_read: datetime the reading was uploaded and taken by the sensor, respectively
235_v_median, 235_i_median, 275_v_median, 275_i_median: median values for the 235 nm and 275 nm LED voltages and currents for that reading, in V and A respectively (as described in the paper, these are medians of the 10 individual readings taken per sensor read)
235_temp, 235_rh, 275_temp, 275_rh: temperature and relative humidity values taken from sensors on the 235 nm and 275 nm LED boards in °C and %
235_pd_median, 235_pd_max, 235_pd_ptp, and their 275 nm equivalents: medians, maximums, and peak to peak spans of readings from the photodiode of each optical path across the 10 readings taken for the sensor read
235_ra_median, 235_ra_max, 275_ra_median, 275_ra_max: median and maximum right angle photodiode responses for each optical path, as described in the manuscript
nitrate_concentration_mg_L: nitrate concentration in mg/L; this is only present for the clean water calibrations.
We also provide a folder "ott", which contains the data from the OTT Hydromet reference sensor for the dirty water experiment. We only use the datetime and nitrate concentration columns from these data files.
All of these files are processed by the provided analysis code.