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Ref. No. [UMCES] CBL 2015-011
ACT VS15-04
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Figure 3.
Time series of the Troll 9500 pH test instrument pH results along with the dye reference pH
results for the complete ten week lab test. Results include nine rapid pH transition tests conducted at each
temperature and salinity condition. Detailed plots of each transition test are provided in Appendix I.
Lab testing results were further examined for the stable portions of each of the source
waters and these data do not include any of the pH shifts or temperature shifts. For the seawater
trials, salinity was maintained within 0.12 units (range = 35.14 to 35.26) with an average of
35.19 and temperature was maintained to within 0.8 for each set point (Fig. 4 top). The first
temperature trial ranged from 20.07 to 20.88, with an average of 20.27
o
C., the second
temperature trial ranged from 9.98 to 10.64
o
C, with an average of 10.12
o
C, and the third
temperature trial ranged from 29.77 to 30.53
o
C, with an average of 29.90
o
C. Time series results
of the Troll 9500, Metrohm data and reference pH data are shown in middle panel and the time
series of the calculated difference between instrument and reference pH are shown in the bottom
panel. The average difference between the Troll 9500 and reference pH for the stable seawater
component was 0.16 ± 0.04, with a total range of 0.11 to 0.22 (N=59).