Post-deployment Check

After you recover the sonde and record the fouling drift measurements:

• Transport the sonde (with the guard on and still running) in either a wet white towel or in a vented white cooler with wet foam to saturate the air. This will allow the sonde to continue to collect DO data in a saturated air environment while in transit to the lab.
• At lab, place sonde in a 5-gallon bucket of saturated tap water for overnight data collection.
• Post-calibrate the cleaned sensors the next day.
  - Turbidity +/- 3% or 3 ntu whichever is greater
  - Dissolved oxygen +/-0.5 mg/L, 6% saturation
  - pH +/- 0.5 standard units
  - Specific conductance +/- 5%
  - Temperature +/- 0.15 degrees C
  - Depth +/- 0.2 cm at 1 m
• Make sure that the turbidity wiper is removed, cleaned and replaced by a clean spare before post-calibrating the turbidity sensor.
• Document drift and combine with field notes for final QA.

Data QA/QC

Your investment in a monitoring station should include confidence in the data . It's important to establish a valid QA/QC process. As continuous monitoring technology develops, more data are generated that need to be checked.

Software is a great way to deal with this volume challenge and new software packages are available to assist you in your Quality Assurance record keeping. However, each agency may have its own best-practice process, especially concerning fouling and drift correction of the data.

Data Analysis Software

AQUARIUS Time-Series: Database software designed for water quality and quantity data sets. Advanced data analysis, rating, correction, and visualization capabilities.
Streamline-ENV: Data collection software designed specifically for YSI instruments. Excellent reporting, calibration and data management features.