@idg
theire are 3 kinds of radiation:
1. aplha rays (high speed helium nucleus) zero danger outside the body (the skin stops the alpha ray)
high danger if the radioactive substance emiting it is inside the body
2. beta rays (high speed electrons) low danger outside the body (penetrates the skin by a few milimeters)
medium danger inside the body
3. gamma rays (high energy EM) high danger outside the body (goes through the whole body)
low danger inside the body
You are right does dosimeter work on the basis that ionisation occures as the rays go through the detector.
Alpha and beta rays are strong ionising rays while gamma rays dont realy ionise that strongly. So a dosimeter will have difficulties recording gamma rays.
That building where you headquaters seems to have a high contamination of radon
(I believe they radiate alpha rays, but i am not sure would have to look that one up) gas produced by the decay of uranium inside of granit.
I dont know how much the dosimeter measured on the ground but one shouldnt underestimate the risk caused by radon. Maybe they should get better ventilation at the headquater to reduce the level of radon.
Comming back to how to measure the radiation on the plane. Probably a semconductor detector would to the trick of measuring the gamma rays. Im not sure how expensive they are but they are definatly more expensiv than any dosimeter (1000-10000 ¤/$).
Hope this was helpfull.
It is calculated according to the sectors flown, average altitude and latitude, flight time and so on.
@I-FORD
These figures would only be correct by normal sun activitys. If theire is a high sun activity those numbers should be higher.