YSI BOD Analyst Pro - Manual (Page 26)

YSI BOD Analyst Pro ® User Manual 26
Dilution Blank
If checked this is a dilution blank test. Only the depletion is calculated for these tests. There is no
BOD value calculated. The Maximum Dilution Blank Oxygen Depletion criterion is applied to
Dilution Blank Tests. By default this is 0.2 mg/L, but may be changed by the user.
Used as Seed
If checked the sample can be used as a seed and will therefore appear in the Seed list for each
Sample. When “Used as Seed” is checked, a seed correction will be calculated for the sample and
used in determination of the BOD for each bottle in the Sample.
CBOD
If checked the sample is reported as a CBOD (carbonaceous BOD). Checked or not this has no
affect on the calculations. CBOD is typically reported when denitrification inhibitor is used in the
BOD test.
Decimal Points
The value chosen dictates the number of digits to the right of the decimal point in reporting of the
final BOD for the sample. The default is 0.
Pre-dilution
The pre-dilution factor is used when the General Setup Form option is checked for Pre-dilution.
Very strong samples sometimes require dilutions that would be difficult to make in one step. In
these cases a sizeable quantity of sample is first diluted to a ratio that will make the final dilutions
practical. In BOD Analyst Pro software, this is called pre-dilution.
For example, if you add 10 ml of your dairy farm sample to a 1000 ml volumetric flask and then
fill the flask with dilution water, this would be a pre-dilution of 100. It is sometimes referred to as
a serial dilution. You may find it easier to adjust for the strength of each sample with the pre-
dilution while keeping the final dilutions constant for all samples. Seed control samples and
blanks can not be pre-diluted.
Quality Control
Used in the trending graph / stats function Quality Control Limits may be set in this field and
viewed under Stats (Statistics). For example, when analyzing many weeks of BOD values for a
sample the standard deviations (SD) of a given sample may be expressed in QC limits. The
control limits could be 3SD while the warning limits could be 2SD of the mean value. See more
detail under the Trending section of the manual.
2.4 CHANGING A SAMPLE
Use the tool button bar to move to the sample (record) you want to change. Edit the fields as
required. Changes are automatically saved when you click OK to exit the Sample Setup Form.
When you edit a Sample Name the new name will also appear on reports of “old data”. For
example, if you edit the Sample "clarifier," and change its name to "secondary," when you print a