Awareness Technology Stat Fax 4200 Operator's Manual page 50

Cut Off Mode (Continued)
Set the Controls by selecting the appropriate control field.
Note: When setting the Controls, if there are Replicates, the Location will be the starting
location. If the Controls or their Replicates overlap due to the plate setup, an error flag will
display while running the test to warn the operator. (Reference Section
Selecting the 'COV =' field will open the Select COV Formula screen. In addition to the
universal equation, Stat Fax
Where COV is the Cutoff Absorbance Value, mNC is the mean of the Negative Controls;
mPC is the mean of the Positive Controls. X, Y, and F are user-entered coefficients that
can have any positive or negative numerical value including zero and 1.
See explanation
of choices in
the table below.
Highlight the desired formula from the list and press the Select button.
COV Formula
X*mean(NC) + Y*mean(PC) + F
X * mean(NC) + F
46 Stat Fax
4200 offers three more optional formulas.
®
Select COV Formula
X*mNC+Y*mPC+F
X*mNC+F
y*mPC+F
X*mCC+F
COV Formula options
Universal equation, used to calculate the cutoff
value based upon readings or positive and/or
negative controls.
• In this equation, NC and PC are used to determine
the COV (cutoff value).
• Enter the variables provided in the package insert.
The software calculates the mean of the positives
and the mean of the negatives.
• Use this equation if only a negative control is used
to determine the COV.
® 4200 Operator's Manual Doc. 4200 Rev. K
2.4.2.1)
Exit
^
v
Select
Explanation