Peak Editor

 

Analysis condition defaults for metal stoichiometry factors can be set using the sample information metal table editor. Stoichiometry factors can also be set for each pulse chemisorption experiment using the analysis conditions experiment step editor. If required, stoichiometry factors for a completed pulse chemisorption experiment can be viewed and modified using the peak editor’s stoichiometry settings window.

The Peak Editor feature provides the viewing and editing of up to 16 dynamic analysis experiments. The Peak Editor options are accessed by opening a Completed sample file and selecting a "Peak Editor" entry from the drop-down menu at the bottom of the report window. Peaks can be defined, edited, or deleted.

Peaks are defined by a baseline. If the Find All Peaks button is clicked (enabled when Edit Peaks is selected), the Peak Editor will define baselines for all positive peaks detected according to the Integration window accessed from the Integration button. For Loop calibrations, peaks are found using events that occurred during the analysis — such as the time an injection started — instead of peak detection options. The baseline can be manually defined by double left clicking in the signal graph on the starting baseline point (this places the Peak Editor into baseline creation mode). The ending baseline point is then defined by left clicking in the signal graph on the ending baseline point. Baseline creation mode can be exited by right clicking in the signal graph.

Peak Editor View

Open a Sample File

When a sample file with a Complete status is opened, three views are available:

  • Overlay Experiments View
  • Stacked Experiments View
  • Peak Editor

To change the view, select the view from the drop-down list at the bottom of the graph window. Only the Peak Editor view allows editing of the experiment.

Example of
Overlay Experiments view
Example of
Stacked Experiments view
Example of
Peak Editor view
Peak Editor
Selections Description
Calibration
[button]

Calibration. Select a previously defined calibration file. If the experiment and calibration gases differ, a warning displays. The system also compares the experiment flow rate and calibration flow rate. If they differ, a warning displays.

Experiment Information

  • Description. Enter a description of the current experiment.
  • Type of analysis. Select the analysis type that most closely describes the current experiment. This will affect what is reported as part of the Summary report data and the available reports.
  • Vapor. Select a vapor before creating or applying a vapor calibration. This field is only visible for vapor experiments.  
  • Loop volume. Displays the volume of the gas injection loop.
  • Ambient temperature. Displays the ambient temperature entry from the Options > Environmental Defaults setting. This field may be edited.
  • Atmospheric pressure. Displays the atmospheric pressure entry from the Options > Environmental Defaults setting. This field may be edited.
  • Active concentration. Displays the percent of the gas mixture which is composed of the reactive gas versus an inert filler. This value is used for data reduction, including pulse chemisorption.
  • P0 of adsorbate. Displays the saturation pressure of the adsorbate.
  • Adsorbate cross-sectional area. Displays the area that a single adsorbed molecule occupies on the surface of the sample. It is used in surface area calculations.
  • Manual Injections. Displays the injection settings entered during analysis. This table may be edited.

Create Calibration. Create a signal calibration from the currently selected experiment.

Delete [button]

Clears all peaks from the table and removes all markings from the peaks.

To delete a single peak, select the peak from the peak table or left click the peak to enable the Delete Peak button.

  • Delete All is available only when the Fit Peaks selection is enabled.

  • Delete All Peaks is available only when the Edit Peaks selection is enabled.

  • Delete Peak is available only when the Fit Peaks selection is enabled.

Delete Baseline
[button]

Removes the baseline from the graph.

Available only when the Fit Peaks selection is enabled.

Display Options
[group box]

Use to change how the data are displayed.

Zero. Select to zero the signal (starting baseline).

Invert. Select to invert the signal (peak).

Hide Peak Marks. Select to hide all marks from peaks.

Smooth. Select to smooth the signal on the display.

  • Order and Window. Enabled when the Smooth checkbox is selected. The smoothing process uses the Savitzky-Golay filter to fit a polynomial order n into size of the specified window [m].

Find All Peaks [button]

Defines baselines for all positive peaks detected according to the Integration window, accessed via the Integration button. Loop calibrations do not use Integration button settings when finding peaks.

Find All Peaks automatically detects the peaks and draws the baseline for detection. Place the cursor over one of the baseline end points and double left click to grab the baseline. Move the cursor to the new position and right click. Available only when the Edit Peak selection is enabled.

Gaussian [drop‑down box]

Standard Gaussian curve. Available only when the Fit Peaks selection is enabled.

Import M.S. [button]
Remove M.S. [button]

Mass spectrometer data can be imported and overlaid in the Overlay Experiment view. In the Peak Editor view, it is saved as a separate signal.

Import M.S. Click to import mass spectrometer data. In the bottom right-hand corner of the pop-up window, select the type of mass spectrometer file to import (Quadera, Quadstar, MKS, or TAMS). Select the file, then click Open to import the signals.

A popup window prompts the user to sync the temperature data with the current experiment temperature data.

Remove M.S. Click to remove all previously imported mass spectrometer signals from the current experiment.

Import standard peaks [button]

Imports the saved peak parameters from the Edit Peaks view. Available only when the Fit Peaks selection is enabled.

Integration Options
[button]

See Peak Detection / Integration Options.

Interpolation [button]

Interpolate Temperature. Select to interpolate the temperature. Click Range to specify a temperature range. Slide the blue bars on the graph to indicate the range.

Log Normal Skewed [button] A 4-parameter, log-normal shape that allows for skewed peaks. This is the default peak. Available only when the Fit Peaks selection is enabled.
Peak fit model
[button]

Select the peak shape. Available only when the Fit Peaks selection is enabled. Options include: Gaussian, Lorentzian, Pearson type VII, Pseudo-Voight, and Log Normal Skewed (3 and 4).

Sample mass
[text box]

Calculates the mass-specific quantities. Initial value is taken from the sample information at the start of the analysis.

Snap to Signal
[button]
Places the selected baseline point on the signal curve.
Stoichiometry
[button]

See Active Metals for Chemisorption Analyzers.

View Type [group box]

Edit Peak. Locates peaks via signal integration over a baseline.

Fit Peaks. Locates peaks via function fitting to minimize residual over a baseline.

  For fields and buttons not listed in this table, see Common Fields and Buttons.