Bomem-GRAMS User's Guide

More documents

Recommendations

Info

Section 4.1 Description • Halt current collect and loose data halts the current data acquisition and erases all data. • Halt current collect but keep data accumulated up to now halts the current data acquisition and saves data acquired so far. • OK performs the selected action. • Cancel cancels the Halt Collect command and allows data acquisition to continue. 4.1.6 Help The Help command provides access to the About Bomem-GRAMS dialog box and to Help Using Bomem-GRAMS. 30 Bomem-GRAMS User's Guide
APPENDIX A APODIZATION FUNCTIONS A.1 Purpose Bomem-GRAMS uses apodization functions to correct the Fourier transform process for artifacts that are introduced by the abrupt truncation of the interferogram when the instrument reaches the limit of its scan. Apodization, or “foot removal” consists of multiplying the interferogram by a function that causes its intensity to fall smoothly to zero at its ends. This reduces the feet (side lobes) of the interferogram, thus reducing the artifacts. However, it also increases the line width (degrades the resolution) of the spectrum. Bomem-GRAMS offers a large selection of apodization functions. However, we recommend that you use the cosine function as a general-purpose apodization function. A.2 Functions available in Bomem-GRAMS The following table lists all the apodization functions available in the Bomem- GRAMS acquisition interface and gives a brief description of how they affect the spectrum. FWHH: (Full Width Half Height) is the theoretical width of a monochromatic line at half its peak height compared with the apodized resolution requested, in percentage. SLAM: (Side Lobe Amplitude Maximum) is the theoretical amplitude of the largest side lobe compared with the amplitude of the main peak, in percentage. D: is given by Optical _ path _ difference maximum_optical_path_difference Name and description Function FWH H (%) Boxcar No apodization. Side lobes diminish as 1/x. Line shape given by sinc x Bartlett (triangular) Triangular function; all side lobes positive, side lobes damped out as 1/x 2 ; intermediate half width. Line shape given by sinc 2 x 1 60 20 ( 1 − D) 89 4.5 SLAM (%) Bomem-GRAMS User's Guide 31
Page 1: Bomem-GRAMS User's Guide This manua
Page 4 and 5: No right to print, copy, in whole o
Page 7 and 8: T ABLE OF CONTENTS About this Manua
Page 9: ABOUT THIS M ANUAL Audience a This
Page 12 and 13: Section 1.1 Check the signal Figure
Page 14 and 15: Section 1.1 Check the signal Figure
Page 16 and 17: Section 1.3 Acquire a sample spectr
Page 19: CHAPTER 2 BOMEM-GRAMS 2.1 Descripti
Page 22 and 23: Section 3.2 Computer requirements 3
Page 24 and 25: Section 3.3 Software installation F
Page 26 and 27: Section 4.1 Description Parameter S
Page 28 and 29: Section 4.1 Description b The recom
Page 30 and 31: Section 4.1 Description • Buffer
Page 32 and 33: Section 4.1 Description Threshold d
Page 34 and 35: Section 4.1 Description Number Iden
Page 36 and 37: Section 4.1 Description j For trans
Page 38 and 39: Section 4.1 Description • Instrum
Page 42 and 43: Appendix A Apodization Functions Na
Page 44 and 45: Appendix B Array Basic Interface Ar
Page 52 and 53: Appendix B Array Basic Interface Er
Page 54 and 55: Appendix B Array Basic Interface Er
Page 57 and 58: APPENDIX D GLOSSARY Note: The follo
Page 59 and 60: Appendix D Glossary blank sample A
Page 61 and 62: Appendix D Glossary Fast Fourier tr
Page 63 and 64: Appendix D Glossary nonlinearity A
Page 65 and 66: Appendix D Glossary Lowering the re
Page 67 and 68: Appendix D Glossary The transmittan
Page 69: A Align............................
Page 72 and 73: general parameters initial delay...
Page 76: Analytical and Advanced Solutions 5

Bomem-GRAMS User's Guide

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?