Xylem EXO Series - Page 20

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aected by the UV absorbance of the DOM in the water. Testing shows that underlinearity can occur at fDOM
concentrations as low as 50 QSU. is factor means that a eld sample with an fDOM reading of 140 QSU will
contain signicantly more than double the fDOM of a sample that reads 70 QSU. is eect—good linearity
in colorless quinine sulfate solution, but underlinearity in stained eld samples—is also exhibited by other
commercially available fDOM sensors and thus the performance of the EXO sensor is likely to be equivalent
or better than the competition while providing the advantages of easy integration into a multiparameter
package and automatic mechanical cleaning when used in monitoring studies with an EXO2 sonde.