Direct Calibration for the Kratky Camera

For the classical slit-focus camera the result of the integration is [89] 

21) the normalization to the scattering cross-section r leads to the definition of absolute intensity in electron units which is common in materials science. If omitted [90,91], the fundamental definition based on scattering length density is obtained (cf. Sect. 7.10.1). 

A Practical Hint . In order to most accurately determine H in Eq. (7.21), a mathematical theorem concerning convolution of a function with a shape function are helpful. The measured primary beam profile of the Kratky camera 

It is thus reasonable to make the slit height H of the detector slit wider than the integral breadth of the intrinsic primary beam profile. In this case the observed integral breadth equals H - and can be accurately determined from the measured primary beam profile. 

The absorption factor of the studied sample is measured by means of the moving slit device, as well. For this purpose the sample is mounted in the sample holder and the moving sUt measurement is performed. We measure Ns = 50031 in 16 scans. Because the heights of the moving and the fixed vertical slits are 2 cm, the moving slit registers the SAXS as well - as is required from the definition of absorption. Then 

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