Performance Verification Statement for the XYLEM EXO2 Dissolved Oxygen Sensor

Ref. No. [UMCES] CBL 2016-015

ACT VS16-06

standard deviation of the measurement difference over the total deployment was 0.37 ± 0.10 mg/L

with a total range of -0.06 to 0.56 mg/L. The drift rate of instrument offset, estimated by linear

regression (r

=0.85), was 0.009 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

ted by EXO2 sonde 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 –

Reference 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.