Bio-Rad Image Lab™ Software - Manual (Page 171)

Volume Tools
User Guide | 171
Volume Types
You can define the volume type (unknown, standard, or background), the quantity of
standard volumes, or enter a custom name to replace the default label.
Unknown volumes are volumes you want to quantify.
Standard volumes are used for absolute quantities. See Absolute Volume Quantity
on page 173 .
Background volumes are used to remove the background from the calculation. The
result of volume background subtraction appears in the Adjusted Volume column of
the analysis table (Volume Table tab).
Note: This volume type needs to be assigned only when using Global
Background subtraction.