How do I calibrate my U24-001 Water Conductivity Logger Data?

A:

a.      Using a calibrated field conductivity meter, measure the specific conductance (the conductivity adjusted to 25C) of the water after the logger has been launched, deployed, and temperature stabilized (approximately 15 minutes).  Record the specific conductance value (micro Siemens/cm), date, and time. 

b.      At the end of the deployment, use the calibrated field conductivity meter to measure the specific conductance and record the specific conductance value (micro Siemens/cm), date, and time before removing the logger.

c.       Once the logger is removed and the data is downloaded, you can process the data, using The Conductivity Assistant to calculate for either channel the specific conductance versus time using a selectable temperature coefficient of 2.1 % / ^oC, for salt water, natural water compensation per EN27888, or a customer selectable temperature coefficient.  The temperature compensation selected must match the temperature compensation used by the field conductivity meter.

d.      To calibrate the data, in the Calibration Box of the Conductivity Assistant:

                                                              i.       Select “Use measured points for calibration”. 

                                                            ii.      Check the “Starting calibration point =” box and enter the specific conductance value that you measured in step a.  In the drop down menu for “Measurement Time” select the first date/time after your recorded date and time from step a.

                                                          iii.      Check the “Ending calibration point =” box and enter the specific conductance value that you measured in step b.  In the drop down menu for “Measurement Time” select the first date/time before your recorded date and time from step b.

                                                           iv.      Click “Create New Series” to see plots of the input and processed/calibrated data.  The Conductivity Assistant can be rerun many times, with and without calibration data, because it does not affect the downloaded, raw data from the logger.

e.      You can now clean the sensor and redeploy the logger per step a.  The two point calibration process described above compensates for sensor drift and sensor fouling.