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Ref. No. [UMCES] CBL 2015-014
ACT VS15-07
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A cross plot of all corresponding EXO-pH2 versus reference pH results is shown in
figure 12. The instrument performance was slightly variable among water types with slopes and
regressions ranging from 0.43 (r
2
=.75), 0.69 (r
2
= .99), and 0.89 (r
2
=0.94) for salt, brackish, and
fresh water tests respectively. The overall linear regression through all of the data had a slope of
0.72 with an intercept of 2.26 (r
2
= 0.88). The mean and standard deviation of the calculated
difference between the EXO-pH2 measurement and the reference pH for all matched pairs within
the three stable testing periods was 0.04 ±0.10 (N=197)
Figure 12.
Cross plot of Xylem EXO-pH2 measurements against the dye reference pH measurements for
201 matched observations during the stable Temperature and Salinity portions of the entire lab test.