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Ref. No. [UMCES] CBL 2016-013
ACT VS16-04
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hypolimnion. The HOBO appeared to reach equilibration during the 7 minutes and ended with a
final offset of around -0.2 mg/L. The range in measurement differences between instrument and
reference was -0.15 to 1.78 mg/L for cast 2 and -0.92 to -0.17 mg/L for cast 3.
Results for the HOBO U26 for the two Lake Michigan trials are shown in figure 16. The
HOBO had a slight positive offset of 0.3 mg/L during surface equilibration and then exhibited a
strong negative bias (-3.0 mg/L) when rapidly transitioned to the cold high DO hypolimnion. The
sensor did not fully equilibrate after 7 minutes and ended at -1 mg/L against the reference after
seven minutes. For cast 2, there was an initial negative offset of -0.5 mg/L when equilibrated in
the hypolimnion and a positive bias (3.1 mg/L) when rapidly transitioned into the warm, normoxic
surface water. The sensor did not fully equilibrate after 7 minutes and ended at -1.1 mg/L against
the reference after seven minutes. The range in measurement differences between instrument and
reference was -3.03 to 0.40 mg/L for cast 1 and -0.81 to 3.05 mg/L for cast 2.