YSI BODAnalyst - Manual (Page 31)

Taking Initial DO Readings Section 6
YSI Incorporated BOD Analyst for Windows Software 27
The fastest and easiest way is to set Technique: to auto. After the bottle number is entered the
program will store the reading as soon as it is stable. Entering the bottle number then, is an
implied confirmation of the soon to be stable reading.
6.3 ALARMS
Alarms are provided for temperature and supersaturation.
You can specify a range of temperatures for initial DOs and a different range of temperatures for
final DOs. Just before storing a reading the program will check the temperature. If it is outside
the range, then the program will display a warning message on the YSI 5100 DO Instrument, for
example
If you do not want to store the reading, press SKIP and you can take steps to remedy the situation.
If you want to store the reading anyway press CONFIRM.
It is common to collect a sample in cold weather that is over 10 mg/L. While a 10 mg/L sample
is not supersaturated at low temperatures, it is at 20
°
C. If such a sample is placed in the
incubator, it is likely that it will outgas and cause erroneously high BOD. The supersaturation
alarm will warn you that the reading is above the value that you have specified. It indicates that
there is a risk of supersaturation. The warning is as follows:
If you do not want to store the reading, press SKIP and you can take steps to remedy the situation.
If you want to store the reading anyway press CONFIRM.
All of the alarm settings are on The YSI Instrument Parameters Form. See Section 11.5 for
detailed instructions.
6.4 DERIVED INITIAL DOS
If you have checked the Derive initials field on the General Setup Form, then the program will
automatically derive initial DOs for you whenever it can. You can always write over a derived
initial DO by simply storing a measured reading to that bottle. Let's go back to the batch that we
were working with and let's start just after we've stored our blanks.
Temp 24.3 high
Store anyway?
Supersaturated
Store anyway?