Resolving power of the spectrometer

Atomic emission instruments have resolving powers in the order of 30000 to 100 000. The use of a wide exit slit (bandwidth perceived by the photomultiplier tube) degrades the resolving power of the spectrometer. 

A. Measure the width at half-height of the peak at mlz 53 and calculate the resolving power of the spectrometer from the expression m/mm. Would you expect to be able to resolve two peaks at 100 and 101 Da ... 

The two peaks near mlz 31.00 in Figure 22-9 differ in mass by 0.010 Da. Estimate the resolving power of the spectrometer from the expression ml Am without making any measurements in the figure. 

Figure 3.3-17 Relation between the optimal spectral band width Ai>o = t /Rp and the line width AC i/2, Rq is the resolving power of the spectrometer. For a the sensitivity is low since the spectral band width is larger than the line width, also the background contributes to the noise, for b the resolution of the spectrometer is sufficient to yield a high sensitivity, c Relation between bandwidth and resolving power.

AA is the difference in wavelength between two spectral lines of equal intensity. Two peaks are considered resolved if the distance between them is such that the maximum of one falls on the first minimum of the other. Atomic emission apparatus have resolving powers in the order of 30 000 rising to 100 000. The use of a too wide exit slit (bandwidth arriving on the photo-multiplier tube) reduces the resolving power of the spectrometer. 

IV.lb) High mass resolution The true Isotope mass differs slightly from its nominal Integral value ("mass defect"). If the mass resolving power of the spectrometer exceeds the ratio of the integral mass to the mass defect, then two Isotopes at the same Integral mass can be separated. For in-... 

C is independent of p/y if the band is Lorentzian in shape (independent of the resolving power of the spectrometer). 

Early attempts for experimental measurements of infrared intensities [13,14] resulted in greatly divergent values for the same molecule. It was soon realized that most of the difficulties were associated with the low resolving power of the spectrometers used [IS]. The problems arise from the fact that the incident infrared beam emerging from the monochromator is not strictly monochromatic, but contains a band of frequencies around die frequency v determined by the slit function g(v,v ). There is, thus, a perfectly good chance for the intensity of the transmitted radiation I by a cell... 

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