Mass Tab - Mass Spectrum
The Mass Tab consists of 4 sections: Mass-Spectrum, Time-Of-Flight Spectrum, Voltage Correction and Hit-Position Correction. The sections are designed to work independently but they also share information
When clicking on the Mass Tab an empty Mass Spectrum page is first opened. On the left side there are some parameters that are needed to calculate the mass of every event.
On the lower part there are several buttons:
- Refresh: Calculates the Mass-Spectrum and also updates the Mass Windows.
- Use Voltage Correction: When green the voltage correction factors are used on the masses
- Use Hit-Correction: When green the Hit-Position correction factors are used on the masses.
- Identify Peaks opens the Peak Identification window.
- Alignment Mode: When green you can aling peaks to a certain position.
- Calculate Mass: Calculates the mass of every event and creates a Mass Spectrum Chart which is displayed in the center of the screen. Also if there are any Mass Windows loaded with the project they are listed on the right side of the screen. The picture below show how these looks
Here you can modify the Mass Window ranges using simple mouse controls as follows.
- You can select a mass window by clicking on its name in the table on the right or by left clicking on its region on the chart
- You can move a mass window by holding the middle mouse button (scroll bar) and moving the mouse to the desired position.
- You can move the borders of a mass window by holding the right mouse button and moving the desired border to the new position
- In order to move the mass window or any of its borders a mass window needs to first be selected.
Clicking Alignment Mode will change the color of the background of the button to green and change the cursor to a crosshair. Then clicking anywhere on the mass spectrum will find the highest pek around the cursor and open the Alignment window.
Here you are shown the position of the peak and how high it is. You have to enter the correct value where that peak should be and click Calculate FlightLength. Keeping the Time Offset constant the Flightlength will be adjusted to send the peak to the position specified. Then the mass spectrum is recalculated using the new values.