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Ref. No. [UMCES] CBL 2016-012
ACT VS16-03
30
The time series of the difference between instrument and reference DO measurements for
each matched pair (n=118 observations) is given in the bottom panel of figure 2. The average and
standard deviation of the measurement difference over the total deployment was 0.333 ± 0.447
mg/L with a total range of 0.248 to 0.485 mg/L. There was no measurable trend in instrument
offset during the entire deployment (linear regression: r
2
=0.003; p=0.58) as a result of either
biofouling effects or calibration drift.
Figure 2.
Time series of DO measured dete
c
ted by SBS HydroCAT deployed during the 15 week Great
Lakes field trial.
Top Panel
: Continuous DO recordings from instrument (blue line) and DO of adjacent
grab samples determined by Winkler titration (red circles; yellow circles represent adjusted reference values
).
Bottom Panel
: Difference in measured DO relative to reference samples (Instrument DO mg/L – Ref
DO mg/L) observed during deployment.
Insert:
Close up of excursion that occurred 4/8-4/9. No reference
samples were collected during this time period.