Which of the dosimeters/radiometers can you recommend?

Question

Iron

The crux of the problem:
Recently, on Habré, I often see topics about self-assembly of dosimeters-radiometers or about commercial projects of a similar theme. Those. there are experts.
There are a sufficient number of radiometers on sale in different price ranges, for example www.mydozimetr.ru/catalog/6 (the store was taken at random). But in descriptions and forums, the level of marketing goes off scale.
What mandatory set of functions should be in the device? What functions are useful, but for example, are there in more expensive devices (color screen and bluetooth do not count;) Which device for different price ranges will be better.
Or advise a specialized forum, preferably with a FAQ.

Answer 1

publ.lib.ru/ARCHIVES/P/POLENOV_Boris_Vladimirovich...
An old but understandable book on the basics.