Peak integrals
This module is used to integrate the area under peaks.
Getting started
Peak integration is usually only performed on individual peaks.
Step 1: Defining integral ranges
- Activate the "Add ranges"mode by pressing the "+" button.
- Double-click on the graph at the position where the first range starts.
- Move the cursor to the position on the graph where the first range ends. Double-click to set the end position.
While dragging the mouse cursor, the range is indicated visually.
- Repeat steps 2 and 3 to add more ranges.
- Then disable the "Add ranges" mode by clicking the "+" button again.
Integrals Φ are automatically calculated for each scan in each range as follows:
Φ = ∑ Δ⋅Ii
where i is the index of the data point within the range, Δ is the stepsize, and Ii
is the measured intensity of data point i.
Step 2: Subtracting the background
Normally the area between 0 and the measured intensity is integrated. To only integrate the area between the background
curve and the measured intensity, a simple linear background interpolated between the first and the last data point in
the range can be activated. Click the button "subtract linear background" to activate background subtraction.
The integrals are updated automatically.
Centering the integral ranges
Integral ranges can automatically be centered on the peaks:
- Highlight the ranges to be centered by clicking on their names in the table.
- Click "Shift all selected ranges..." (button ">|<") to shift the selected ranges until the center lines lie on the
highest intensity in the range.
The width of the ranges is not changed by centering. Integrals are updated automatically.