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Integration

Integration

Interactive, or manual, integration allows the user to define the start and end of each sub-integral, and set a scaling factor. Auto-integration is also available.

Enter the integration subroutine from the Process menu or by typing ID.

A gray integral line is displayed covering the entire spectrum. Note that if the integral line is not flat over regions of flat baseline, you need to exit the integration routine and correct the baseline with FB or QB.

Integrating individual peaks (sub-integrals):

As soon as the cursor is moved within the spectrum window, the cursor changes to a vertical red line. Place the red line to the left or right of the peak and click the left mouse button to set one end of the integral region. Move the cursor to the other side of the peak and click the left mouse button again to define the other end of the integral region. Repeat for other sub-integrals.

As soon as the first sub-integral has been defined, the full-spectrum integral is no longer displayed. Only sub-integrals are displayed.

To set the value of a chosen sub-integral to a convenient value, move the vertical red cursor on top of the chosen sub-integral. Do not click the mouse button, just position the vertical red line so it intersects the chosen sub-integral. Type V on the keyboard, and enter the value. All integral values displayed will now be relative to the set value. Note that the integral scaling will remain until and unless re-set by the user, even if the sub-integrals are cleared or a new spectrum is loaded. Changing the vertical scale of the spectrum or the integrals does not affect the numerical values.

The integrals can be scaled vertically using the [ and ] keys, which decrease and increase, respectively, the integral display by 10%.

A list of integral values can be copied to the Clipboard from the Edit menu or by typing B. The list can then be pasted into a text editor or spreadsheet. For example:

    From           To           Area             RelativeArea
    2.853         2.196        529429.6            2.00    
    7.501         6.662       1488150.5            5.62    
    1.284         0.867        793302.2            3.00     

Subcommands active within the ID subroutine:

B – Copy integral list to the clipboard
C –
To clear all sub-integrals
D – Delete the sub-integral at the cursor position
F – Set font for integral labels
L – Delete the Last sub-integral created
S – Show integral labels after exiting the integration subroutine
N – Turn off display of integral labels after exiting the integration subroutine
V – Set the value of the sub-integral at the cursor position
[ – Decrease the vertical scale of the integrals by 10%; does not change the numerical value of sub-integrals
] – Increase the vertical scale of the integrals by 10%; does not change the numerical value of sub-integrals

AI – Auto-integration

Automatic integration decides which sections of the spectrum are peaks, whether or not they are sufficiently well resolved to allow separate integrals to be defined, and sets the integral scaling factor. The operation is dependent on the display mode: when doing a full display, any currently defined sub-integrals are deleted and a new set of sub-integrals is defined. When in a zoomed display, a new set of sub-integrals is appended to any existing set.

The selection of the sub-integral regions depends on the noise and peaks in spectral regions and is very sensitive to the MH (minimum height) value. Also, any sub- integral region the includes zero PPM is ignored (so that TMS is not integrated). The smallest sub-integral the last displayed region when the AI command issued is set to 1.00 by this command.

 


Last updated: 2/6/08