Allow independent time axis

This option is enabled only

a) if overlaying chromatograms are available and if you have selected the Stack option on the Comparison tab page.

b) if Autopurification samples are available and if you have selected the Autopurification option on the Comparison tab page.

Select Allow independent time axis to display separate time axes for the chromatogram stripes.

 Note: 

The unit of the time axis is the same for all chromatogram stripes, even if, e.g., overlaying chromatograms are displayed in the Stack arrangement and if the Allow independent time axis option is selected.

Settings for chromatogram plot

Specify for which chromatogram the settings under Scale time axis (see below) shall apply.

Scale time axis:

Determine how the time axis is displayed for the respective chromatogram. Click the arrow, and then select an option:

• Autoscale or fixed

• Autoscale on peak

Fixed Using formula

Autoscale or fixed:

(Default) Select this option to enter a fixed start and/or end value for the time axis or have Chromeleon determine the corresponding value automatically.

Both Autoscale check boxes are selected by default. In this case, the chromatogram is displayed over the entire retention time during which data were recorded.

Clear the Autoscale check boxes if you want to determine which section of the chromatogram is displayed. Type the start and/or end times in the From and to input fields.

 Note: 

As selected under Time axis units, the unit displayed behind the From and to input fields is either minutes or seconds.

Autoscale on peak:

The Autoscale on peak mode allows you to determine how the chromatogram for the specified peak is displayed. First, click the arrow next to the Selected combo box, and then determine how the peak is selected:

by name

This option selects the peak by its name. A second combo box appears in the same line. Click the arrow to display all peak names that appear in the peak table of the active chromatogram, and then select a name from the list. Or else, directly type the name in the combo box.

 Note: 

If the peak is not found in the active chromatogram, automatic scaling is used.

by greatest height

This option selects the highest peak in the chromatogram.

by greatest area

This option selects the peak with the largest area in the chromatogram.

by number

This option selects the peak by its number in the chromatogram. An edit field appears in the same line. Enter a number by clicking the up or down arrow. Or else, directly type the number in the edit field.

 Note: 

If the entered number exceeds the number of available peaks, the peak with the highest number is used.

by peak table no.

This option selects the peak by its number in the peak table. An edit field appears in the same line. Enter a number by clicking the up or down arrow. Or else, directly type the number in the edit field

 Note: 

If the peak of interest is not found in the active chromatogram, automatic scaling will be used.

The Autosize Width check box is selected by default. In this case, the window width is scaled to the peak width as follows: peak width (from peak start to peak end) + 20%.

Clear this check box if you want to determine the width manually. Type a value in the Width field. .

 Note: 

The unit is either minutes or seconds as selected under Time axis units.

Fixed using Formula:

The Fixed using Formula mode allows you to configure the time axis by using report variables. The following formulas are used by default for the start and end times of the axis: chm.start_time and chm.end_time.

To use different formulas, click the '…' button behind the From and/or to input field, and then select a variable from the Categories and Variables lists. All variables of the following Report Categories are available for selection:

Sample

Chromatogram

Peak Results

Peak Calibration

Peak Table

Peak Purity and Identification

Quantification Method

To use the formula of any other category, type the formula in the corresponding input field. However, please note that the formula will be considered only if it has been entered correctly.

 Note: 

If the system cannot interpret the entered formula as a number, the Autoscale setting will be used instead.

Time axis units:

Determine the unit for the time axis. Select Minutes (min) or Seconds (s).