There are many experimental methods where "counts" are commonly used, not only in XRD. Mostly, it is an arbitrary unit because it is directly related for example to the number of electrons the detector has registered. So it is of course dependent on instrumental operating parameters and settings like acceleration voltage, gain, filters and many more.
There are many experimental methods where "counts" are commonly used, not only in XRD. Mostly, it is an arbitrary unit because it is directly related for example to the number of electrons the detector has registered. So it is of course dependent on instrumental operating parameters and settings like acceleration voltage, gain, filters and many more.
Arbitrary units are used in all sorts of measurements for simplicity sake.
For example if a measurement shows some vales of 18 758 (as the maximum for a measurement), and some other peaks lets say 12 380 and 5 440 when representing your data these values are confusing, that is why we can use Arbitrary units to say that peaks: 18 758 (A.U. = 1), 12 380 (A.U. = 0.66) and 5 440 (A.U. = 0.29), just by seeing the actual numbers it would be somewhat difficult to get the ratio without using simple math.
This makes the data easily digestible with minimal effort from the part of the reader - especially for a reader that is not an expert in the field.
As for counts are usually referred to the actual measurement intensity (things that You detect) as in how many photons land on the corresponding detector lets say at a certain wavelength or at a specific time.