Let Qobs be the observed integrated-intensity count measured by scanning over the reflection profile, and Lobs and Hobs the observed low- and high-angle background counts respectively. The model relating the raw observations of a diffraction experiment to derived parameters may be written as Qcalc = cp Pcalc (vm) + cb Bcalc ~ Qobs, Lcalc = cl Bcalc ~ Lobs and Hcalc = ch Bcalc ~ Hobs. Pcalc is the calculated net integrated intensity per unit inverse scan speed and is a function of vm adjustable parameters describing the crystal structure, the scale factor, secondary extinction and possibly other physical quantities. Bcalc is the calculated count rate per unit time of the mean background and is itself an adjustable parameter. One can see that in general, cp is equal to the time to count the peak divided by the scan width i.e. the effective scan speed allowing for multiple scans over the same peak, cb to the time to count the peak, cl to the time to count the low-angle background and ch to the time to count the high-angle background. It follows that the scan width is equal to cb / cp.
For a classical treatment, the net intensity Pobs may be calculated from the
raw counts by using:
Pobs = [Qobs - 0.5 cb (Lobs / cl + Hobs / ch)] / cp.