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Ref. No. [UMCES] CBL 2016-010
ACT VS16-01
45
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 0.170 ± 0.057 mg/L with a
total range of 0.055 to 0.309 mg/L. The drift rate of instrument offset, estimated by linear regression
(r
2
=0.325), was -0.001 mg/L/d. This rate would include any biofouling effects as well as any
electronic or calibration drift.
Figure 2.
Time series of DO measured dete
c
ted by a JFE AroW-USB 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
:
The 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, bracketed by reference samples.