YSI BOD Analyst Pro - Manual (Page 79)

YSI BOD Analyst Pro ® User Manual 79
Below are brief descriptions of each criterion listed in the Criteria Setup form shown above.
Maximum Dilution Blank Oxygen Depletion (mg/l)
This is the maximum acceptable value for Initial DO minus Final DO in the dilution-blank test.
This criterion is checked only for Dilution Blank samples.
The default value is 0.2 mg/l.
Maximum Initial Dissolved Oxygen (mg/l)
This is the maximum acceptable value for the Initial DO.
This is checked for all tests.
The default value is 9.7 mg/l.
Minimum Final Dissolved Oxygen (mg/l)
This is the minimum acceptable value for the Final DO.
This is checked for all tests.
The default value is 1.0 mg/l.
Minimum (Initial DO - Final DO) (mg/l)
This is the minimum acceptable value for oxygen depletion.
This is checked for all tests except the Dilution Blank tests.
The default value is 2.0 mg/l.
Apply Take 2 Leave 1 Rule
When this criterion is checked (√) the samples must meet the default values just listed in order for
the sample to be used in the BOD calculation.
The BOD test for a sample(s) must deplete ≥ 2 mg/l DO and read ≥ 1 mg/l DO at finals.
Typically one or more of the samples meet the criteria and a BOD value is calculated.
However, if ‘Take 2 Leave 1’ fails for all samples in a group, “2.00” appears for O
2
depletions.
The BOD is calculated but appears as “< [value]” on the bench sheet, indicating not valid.
No Final BOD value is listed for this group on the bench sheet.
There are options that may be applied to help interpret results.
Refer to Section 10.3.1 below for a complete explanation of the options (with examples).
Include Depletion caused by Seed
This criterion refers to the Minimum DO Depletion when Seed DO depletion included.
See the default value above (2.0 mg/l).
If field checked the Seed Depletion is part of the equation.
If field not checked the Seed Depletion is not included in the equation.
Example: If the DO Depletion in the bottle was 2.2 mg/l and Seed Depletion was 0.4 mg/l.
If the criterion was not checked the Minimum DO Depletion would pass (2.2 > 2.0).
If the criterion was checked the Minimum DO Depletion would not pass (2.2-0.4=1.8 or <2).
Minimum Oxygen Depletion % for Seed Tests (%)
This is the minimum percentage DO depletion for Seed tests.
The percentage depletion is defined as Final DO / Initial DO * 100.
This criterion is checked only for samples that are used as Seed.
The default value is defined by the limit 40%.
To turn off the test enter 0% for Minimum.
Maximum Oxygen Depletion % for Seed Tests (%)
This is the maximum percentage DO depletion for Seed tests.