AJA's utility shows 1080p24 ProRes HQ to be 24.7 MB/s where as Apple's white paper gives a target bit rate of 175Mb/s aka 22 MB/s. These equate to 89gigs/per and 79gigs/per respectively (for just video, no audio). ProRes is a variable bit rate codec so there can be small fluctuations in file size between clips of the same duration.
[Ofer Geva]" all recorders that recored a Prores 422 HQ encoded file record the same bit rate?"
Beside the fact that is a VBR codec, it will depend of the hardware you use for the compression.
codecs are sets of rules/recommendations for compression/decompression and they can be implemented with certain variations by different chips, so you may get some differences when using hardware from different manufacturers.