Refer to the Fourier transform infrared spectrum in Figure 19-32.

(a) The interferogram was sampled at retardation intervals of 1.2660 × 10^-4 cm. What is the theoretical wavenumber range (0 to ?) of the spectrum?

(b) A total of 4 096 data points were collected from δ = -Δ to δ = +Δ. Compute the value of Δ, the maximum retardation.

(c) Calculate the approximate resolution of the spectrum.

(d) The interferometer mirror velocity is given in the figure caption. How many microseconds elapse between each datum?

(e) How many seconds were required to record each interferogram once?

(f) What kind of beamsplitter is typically used for the region 400 to 4 000 cm^-1? Why is the region below 400 cm^-1 not observed?

Figure 19-32

Transcribed Image Text:

Background interferogram Sample interferogram Retardation (8) Retardation (8) Sample transform Background transform 4 000 3 600 3 200 2 800 2 400 2 000 1 600 Wavenumber (cm') 1 200 800 400 4 000 3 600 3 200 2 800 2 400 2 000 1 600 1200 800 400 Wavenumber (cm ) Transmission spoctrum 100- 80 60 40 20 4 000 3 600 3 200 2 800 2 400 2 000 1 600 1 200 800 400 Wavenumber (cm") Detector voltage Transmittance (%) Detector voltage