Sensor Calibration Automation Demonstration

1. Sensor Calibration Automation Demonstration Presenters: Barbara Benson and David Balsiger (University of Wisconsin) Collaborators:  Laurence Choi, Yu Hen Hu, Paul Hanson, Tim Kratz, Tim Meinke (University of Wisconsin); Ken Chiu (SUNY-Binghamton)

2. Motivation • Example from current practice: • Sensor calibration: • Due to sensor drift, the Greenspan dissolved oxygen (DO) sensor requires frequent (once every two weeks) calibration services. • Sensor data correction: • After the DO sensor is calibrated, the observed data since last calibration need to be adjusted accordingly.

3. Problem: • Both tasks are performed manually • Labor-intensive process • Does not scale-up well • Solution  Automation • Steps toward automation • Web interface for technician, information manager • Calibration agent integrated into data flow

4. New Calibration Method • Old Method • The Greenspan is manually pulled out of the water and rested for an hour to allow it to stabilize. • The time, air temperature and barometric pressure are recorded and a “correction factor” is estimated manually. • Proposed New Method • A calibrated DO sensor is placed manually next to the existing un-calibrated DO sensor in the water and records data in parallel during “calibration”. • The data recorded from both sensors are entered into a calibration program to calculate “correction factor” automatically. • Potential Benefit • Shorter calibration time • Semi-automated procedure

5. Data “Calibration Period”

6. Steps • Development of computer program modules for the algorithms for calculating the “correction factor” and correcting data • Design of user interface for technician or information manager to execute algorithms

7. “Calibration” Algorithms • Calculating correction constant • Correct un-calibrated data using estimated correction factor

18. Future steps • Extend the program to access the Oracle database for data retrieval and updating • Integrate web interface with the portal • Develop calibration agent(s) • Sensor service manager • Calibration event manager • Data calibration manager

19. Automated Scaling and Data Processing in a Network of Sensors Collaboration with computer scientists at UCSD, Indiana, and SUNY-Binghamton and computer engineering colleague at UW-Madison Growing the Sensor Network: Agents and Remote Code Deployment Calibration Agent NSF NEON Grant: Addressing the Scaling Challenge

20. Calibration Agent(s) • Will detect calibration event • Handle sensors being swapped • Retrieve or capture “calibration” data • Calculate the correction factor • Retrieve data to be corrected • Correct data and load corrected data to the database • Write event data to calibration log in the database

21. A Work In Progress …