Bio-Rad ChromLab™ Software - Manual (Page 255)

Column Performance Analysis
User Guide | 253
Reduced HETP (rHETP) — the reduced plate height, a value used to compare the
efficiency of multiple columns packed with different particle sizes. Columns with
rHETP 2  2 are considered well packed and more efficient. This measurement
requires the medium bed height and the average particle diameter (in

m) for the
column in use. The formula used to calculate rHETP is:
rHETP = HETP/Dp
where Dp = average particle diameter
Analyzing Column Performance
When analyzing the performance of predefined columns, ChromLab obtains the
values for medium bed height and average particle diameter from the column’s
properties table and automatically calculates all measurements.
When analyzing the performance of custom columns, ChromLab automatically
calculates only the number of plates. After you manually enter the values for
medium bed height and average particle diameter, ChromLab calculates the
measurements you select.
All initial values are based on the UV trace. You can change the trace to calculate
measurements based on conductivity.
To analyze column performance
1. Select Analysis > Analyze Column Performance.
The Column Performance pane appears beside the chromatogram. The
Column Performance table appears in the bottom pane populated with the
known values for the column.
2. (Optional) In the Traces section in the Column Performance pane, change the
trace to use.
3. In the Calculate section, select or clear the checkboxes of the measurements to
calculate.