Performance Verification Statement for the XYLEM EXO2 Dissolved Oxygen Sensor

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Ref. No. [UMCES] CBL 2016-015
ACT VS16-06
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Figure K. Long-term stability and thermal stress challenge of the EXO2 Sonde with Optical DO (sn
14J103998). Instrument was maintained in well circulated tank and oxygen content manipulated by
alternately varying water temperature set point between 15 and 25oC several times per week of deployment.
Top Panel: Time series of EXO2 instrument readings representing 15min intervals with discrete values for
Winkler assay of grab samples taken at sensor level. Bottom Panel: Offset in paired DO readings of EXO2
Sonde and Winkler grab samples.