YSI BOD Analyst Pro - Manual (Page 42)

YSI BOD Analyst Pro ® User Manual 42
Data may be entered from the keyboard in a spreadsheet fashion or entered via direct serial
communication with a YSI DO Instrument. Information and data to enter include the bottle
number, amount of sample, amount of seed used, initial dissolved oxygen reading and final
dissolved oxygen reading. For each sample dilution bottle the oxygen depletion, seed correction
factor and BOD are calculated automatically. One exception is the Dilution Blank, for which only
oxygen depletion is calculated. For each set of tests having the same Sample Name, a Final BOD
will be calculated by averaging BODs for the sample. In some samples the individual “bottle”
BODs may not be valid. When tests are checked for validity, the Final BOD is automatically
recalculated using only those tests that meet preassigned criteria.
5.5.2 MARKING/UNMARKING
Tests can be checked for validity using limits set in Criteria Setup. Tests are checked against
limits after final readings have been complete (if the Apply Criteria after final readings is active)
or by clicking the Manual Check button on the Bench Sheet. Tests that do not meet the criteria
are automatically "marked" as unacceptable. Marked data are shown on the screen with a green
background. Tests may also be marked and unmarked independently of the criteria using the
Manual Mark and Manual Unmark buttons. You will learn more about this below.
Upon marking, Final BOD values are recalculated using only the unmarked tests. An example is
shown below. The Marks are explained by clicking on the Sample Name and referring to the
Check Results field at the bottom of the Bench Sheet. In this example the Criteria called for
choosing the Seed Sample bottle closest to 50% DO depletion to use for Final BOD calculation,
therefore the other two dilutions in the series were disqualified and marked as “invalid”. Note that
the Final BOD reading will appear in the first row of the Seed Sample, whether marked or not.