19.1.10.10 Peak Analyzer, Integrate Peaks Page


This page is available in the Peak Analyzer only when Integrate Peaks is selected for Goal in the Start page. It can be used to calculate the areas of the peaks that are found by the Find Peaks page.

PA IntegratePeaks Page.png
  • Menu Command: Analysis: Peaks and Baseline: Peak Analyzer: Open Dialog
  • Window Types: Workbook, Graph

Dialog Theme

Dialog Theme See Peak Analyzer Themes.

Integrate Peaks Controls

Number of Ranges to Integrate Use this to specify the number of peaks that will be integrated. When All Peaks is checked you cannot edit the Number of Ranges to Integrate. Un-check the box and enter a number (N), and only the first N peaks will be integrated.
Integration Window Width Use this to specify the width of the integration windows.
  • Auto: The Peak Analyzer automatically sets the integration window width. The widths will vary by peak.
  • Adjust on Preview Graph: This allows you to move the integration rectangles on the graph to adjust the width and position of the integration windows. Note that if you right-click on integration rectangle of the preview graph, you will get three options:
    • Scale: Choosing this option will open a dialog which allows you to input X values to adjust the integration range precisely on screen. For example if you want the integration to be done exactly from 1.0 to 1.3. You can input 1 into X1 edit box and input 1.3 into X2 edit box.
    • Apply Width to all Peaks: Apply the current peak's left half width and right half width of the integration rectangle to other peaks.
    • Set as Fixed Width to All Peaks: Apply the current peak's left half width and right half width of the integration rectangle to other peaks. Also, Fix Width For All Peaks will be selected in the Integration Window Width group.
  • Fix Width For All Peaks
This allows you to set the Left Half Width and Right Half Width for the integration windows of all peaks. Check Same to use the Left Half Width value for both.
  • Width by Anchor Points
This option is only available when Baseline Mode is set as User Defined on Baseline Mode page. Once you selected this option, the most adjacent anchor points(on left side and right side) of current peak will be used to determine the peak width. Please note, if there is no anchor points before first peak or after last peak while this option is selected, the 1st or last point in input data will be treated as the one-side adjacent anchor point to determine the width of first or last peak.
Left Half Width This is available only when the Fix Width For All Peaks radio button is selected. You can use it to set the left half width of the integration rectangle.
Right Half Width It is available only when the Fix Width For All Peaks radio button is selected. You can use it to set the right half width of the integration rectangle. If the Same check box to the right of this control is selected, the value in this edit box will be set to the value of Left Half Width.
Integrate From This drop-down will not appear if your Baseline Mode was None. Use the drop-down to specify whether you want to calculate the peak area from the baseline or from y=0.
  • Baseline: The Peak Analyzer will find the area between the spectrum data plot and the baseline for each peak.
  • Y=0: The Peak Analyzer will find the area between the spectrum data plot and Y=0 for each peak.
Show Integrated Area Show integrated area on the graph.
Show Peak Index Tag Show peak index tag on the graph.
Integration Result Specifies the destination for the integration result.
Integral Curves Data Specifies the destination for the cumulative integral data. If the box is unchecked, no cumulative data is created.

The Quantities Group

The controls in this group can help you to customize the integrate results which will be output to the range specified by Integrate Result. One column of result data will be generated for each checked box.

Peak Area Peak areas are calculated by integrating the peak data from the baseline or Y=0 (depending on the selection in the Integrate From drop-down list).
Percent Area Output the percent areas that are calculated by Peak Area/Curve Area. This is the percent of each area compared to the area under the whole curve.
Curve Area Curve areas are calculated by integrating the curve data from the baseline or Y=0 (depending on the selection in the Integrate From drop-down list). This value will be the same for all peaks.
Row Index Output the row index where peak center occurs.
Beginning X The X coordinate of the leftmost data point of each peak.
Ending X The X coordinate of the rightmost data point of each peak.
Peak Center The X coordinate of the peak center.
Peak Height The peak height in Y units relative to the chosen baseline.
FWHM The full width at half maximum height or the peak width at half the peak's maximum value for each peak.
Left Half Width The left half width. If we draw a line for y = MaximumHeight/2, this line will intercept with the spectrum data (input data) at two points. Let's denote them as (x_1, y_1) and (x_2, y_2), where x_1 < x_2. Also, we denote the peak center as (x_c, y_c). Then we can compute the left half width as follows:

LeftHalfWidth = x_c - x_1

Right Half Width The right half width. If we draw a line for y = MaximumHeight/2, this line will intercept with the spectrum data (input data) at two points. Let's denote them as (x_1, y_1) and (x_2, y_2), where x_1 < x_2. Also, we denote the peak center as (x_c, y_c). Then we can compute the right half width as follows:

RightHalfWidth = x_2 - x_c

Peak Centroid The peak centroid or center of gravity. Defined as follows:
C = \frac{\int_{0}^{\infty} x F(x) \; dx}{\int_{0}^{\infty} F(x) \; dx}