SATURN-02 D.O.

by | Nov 13, 2012

The table below contains the quality flag associated with dissolved oxygen calbration and sensor performance evaluations and the associated comments, beginning with the most recent.  Refer to the QA/QC general information page for information on the different quality levels.  SATURN-02 may have a different sensor deployed near the surface and at depth.  Because these are different sensors, there are two tables belwo (one for each level).

 

SATURN-02 NEAR-SURFCACE

Quality Flag start time end time depth comment
QL1 5/167/19 11/9/19 all depths 5/17/19 – 11/9/19:  The sensor deployed at SATURN-02 on in May 2019 was checked in 100% aerated DI water prior to and following deployment.  These checks showed that the sensor did not drift or foul during the course of the deployment and the calibration remained within manufacturer specifications (+/-2%).  The data from this deployment have been flagged as good.  See QA/QC supporting documentation for additional details (/saturn03_DO_calibration_evaluation).
QL2 6/27/18 10/26/18 all depths 6/27/18 – 10/26/18:  The dissolved oxygen sensor deployed at SATURN-02 in June 2018 was checked following the previous deployment of this sensor and was found to be reading within manufacturer specifications.  Comparison with quality controlled data from SATURN-03 suggests that the sensor calibration did not drift during the deployment.  A final assessment of sensor drift and data quality will be made once additional quality control data are available.
QL3 5/30/17 11/1/17 all depths 5/30/17 – 11/1/17:  The dissolved oxygen sensor deployed at SATURN-02 in 2017 was checked prior to and following deployment in 100% aerated DI.  The sensor was found to b reading within manufacturer specifications (100% +/- 2%) when deployed and 93.8% following recovery & prior to cleaning.  Following cleaning the sensor read within manufacturer specifications indicating that the drift was due to fouling.   A correction based on the assumption of linear drift during the deployment was applied to the data.  This correction should be considered approximate as the exact onset and progression of fouling is unknown.  Data have been flagged as QL3
QL1 5/27/16 10/12/16 all depths 5/27/16 – 10/12/16:  The dissolved oxygen sensor deployed at SATURN-02 in 2016 was checked prior to and following deployment in 100% aerated DI.  The sensor was found to b reading within manufacturer specifications (100% +/- 2%) in both checks, indicating that the sensor did not drift or foul during deployment.  The data have been flagged as good (QL1).
QL1 5/24/15 10/10/15 1m 5/24/15 – 9/1/15:  The near-surface dissolved oxygen sensor deployed at SATURN-02 in 2015 was checked prior to and following deployment.  These checks showed the sensor to be reading within manufacturer specifications and the data have been flagged as good.
QL1 6/15/14 10/1/14 The dissolved oxygen sensor deployed at SATURN-02 (1m) for the 2014 deployment was factory calibrated prior to deployment.  It was checked  following recovery and read 99.9% in 100% aerated DI.
QL3 6/18/12 10/25/12 1m 6/18/12 – 10/25/12: A mid-deployment check on 6/18/12 verified to be reading within +/-2% of the newly calibrated sensor.  A post-deployment, pre-cleaning calibration check on 10/25/12 found the sensor to be reading ~10% low.  A correction based on the assumption of linear drift of 10% between 6/18/12 and 10/25/12 has been applied to the data.  The correction should be considered approximate as the exact timing and progression of drift are unknown. The data have been assigned a quality level of QL3.
QL1 4/23/12 6/18/12 1m 4/23/12 – 6/18/12: The sensor calibration was checked against newly calibrated sensors on 2/10/12 and again during a mid-deployment check when the buoy was recovered for a short period.  In both of these cases the sensor calibration was verified to be reading within +/-2% of the newly calibrated sensor.

 

SATURN-02 35meter

Quality Flag start time end time depth comment
QL3 5/24/15 10/10/15 35m 5/24/15 – 10/10/14: The calibration was checked in 100% aerated DI prior to deployment and was reading within manufacturer specifications.  The post deployment check showed that the sensor was reading 92.7% in 100% aerated DI.  Following cleaning the sensor reading recovered to 100% indicating that the drift was due to sensor fouling.  Because we lack supporting information on the nature of the calibration drift (gradual fouling over time, vs. a single fouling event), we have not applied any correction to the data from this deployment.  Data may be up to 7% low, especially toward the end of deployment and data should be used with caution.
QL3 6/1/14 10/1/14 35m 6/15/14 – 10/1/14: The calibration was checked in 100% aerated DI prior to deployment and was reading within manufacturer specifications.  The post deployment check showed that the sensor was reading 92% in 100% aerated DI.  Following cleaning the sensor reading recovered to 99.8% indicating that the drift was due to sensor fouling.  Because we lack supporting information on the nature of the calibration drift (gradual fouling over time, vs. a single fouling event), we have applied a correction assuming linear drift from the point of deployment to the point of recovery.  This correction should be considered approximate and data should be used with caution
QL2 4/23/12 10/22/12 35m 4/23/12 – 10/22/12: This sensor was recovered in mid-June and the calibration was checked against several newly calibrated sensors and was found to be good.  A post deployment check was not performed before the sensor was redeployed to SATURN-07 so the extent of drift and fouling cannot be determined.   It is worth noting that while deployed at SATURN-07 this sensor had a fairly consistent offset of about 3.5% with the sensor at Saturn03 (with a verified calibration) during January 2013 indicating that sensor drift has not been extensive.
QL1 4/1/11 10/1/11 35m The sensor was newly calibrated and the calibration was checked and verified in March 2011 prior to deployment of the station mooring.  It was checked again on 10/13/11 following recovery of the sensor. During both checks it was found to be within 1% of a freshly calibrated YSI handheld optode.