Calculating Half Bandwidth of Peak
5.26 Calculating Half Bandwidth of Peak
The half bandwidth of the spectrum displayed currently can be obtained.
Click the
(Half Bandwidth) button on the data processing toolbar. The window shown in Fig. 5-88 will appear. (It is also possible to select the Half Bandwidth (B) command from the data (D) menu.)
Fig. 5-88
5.22 Displaying Data at Specified Wavelength on Spectra
5.26.1 Setting
Enter the desired start wavelength into the start wavelength column.
Calculation Range
Enter the desired end wavelength into the end wavelength column.
Enter the desired peak wavelength into the peak column.
(4) Click the Calculation button. The result of calculation will be
displayed.
Calculation result
Fig. 5-89
The principle of half bandwidth calculation is shown below.
Peak
th
A: Specified value
of peak wavelength
B: Threshold value
Start
End wavelength
th
C: Half bandwidth (B d )
Fig. 5-90 Principle of Calculation
5.22.2
Calculation method
(1) “A” is the value of peak wavelength.
(2) The threshold value “B” is a half of the shortest distance between the point of peak wavelength A and the line connecting the points of tangency of the start wavelength and end wavelength.
(3) The wavelength of the threshold value “B” is calculated by linear interpolation, and that width “C” is the half bandwidth.
5.22 Displaying Data at Specified Wavelength on Spectra
5.26.2 Printing Calculation Result The result of half bandwidth calculation can be printed.
(1) When printing the result of half bandwidth calculation simultaneously with the spectrum, check Print spectrum shown in Fig. 5-91. (Refer to in Fig. 5-88.) When the spectrum is not to be printed, uncheck it.
(2) Click Print, and printing will begin. (Refer to in Fig. 5-91.) The Half Bandwidth window will close when printing is executed. To call
up the same window, click the
(Half Bandwidth) button on the
data processing toolbar again.
Fig. 5-91 Principle of Calculation 3
Fig. 5-92 Example of Printing (with Spectrum Record)
5.22.2
(3) After calculation, click the OK button (Refer to in Fig. 6-91), and the Half Bandwidth window will close, but the result of calculation will be saved.
(4) When the data processing window is being displayed, click the (reset) button on the data processing toolbar, and the calculation result will be reset. Therefore, when the Half Bandwidth window is called up again, “*****” will be displayed in the calculation result column.
NOTE: When file saving is executed after half bandwidth calculation, the last calculation result will also be saved in the file. Therefore, when the Half Bandwidth window is called up, a numerical value
will be displayed in the calculation result column. This value has been saved in the computer, and it cannot be removed even if the reset button is clicked.
5.22 Displaying Data at Specified Wavelength on Spectra
5.26.3 Enlarging To enlarge the scale on the Area window, left-click the mouse.
Scale
(1) Left-click on the spectrum and drag the mouse to draw a rectangle
as shown in Fig. 5-93 to specify the enlarging area.
Fig. 5-93
(2) Release the mouse button while an area is being specified, and an enlarged image will appear as shown in Fig. 5-94.
Fig. 5-94
(3) Double-click the left button on the spectrum, and the scale will
return to the original state.