Hello fellow battle brothers,
I wonder how the diagnostor helmet differs from the normal helmet belongig to the power armour. I mean are the given abilities for the diagnostor helmet (p. 165) in addition to the normal helmet functions?
Or do you ignore the auto-senses ability from a normal helmet (p. 161) and use instead the diagnostor helmet abilities?
From intuition I would suggest to use the diagnostor helmet instead of the normal helmet. Which leads me to my following assumption: Since you do not have a normal helmet you are not granted the dark sight trait. But instead you gain the preysense sight weapon upgrade as normal sight. So, from my understanding preysense sight includes somehow the dark sight trait, since preysense sight states [..] suffers no penalties du to darknes[..] but in addition to that you are granted a +20 bonus to Perception Tests. Which seems very powerfull to me. But again, since you are losing auto-senses if my assumption is correct I think it is rather fair which make the apothecarius a good scout. And last but not least the +20 bonus to perception is granted for Tests at night but I think we can agree that this include dark corridors and thus darkness at a whole.
I mean the following situation would be rather ridiculous:
"What do you see over there Apothecarius?"
"Nothing more than you do."
"I though you have included x-rays in your diagnostor helmet?"
"Yes, but they only work at night and not in the dark corridors of a space hulk..."
Cheers,
Tech Void.