Before Chernobyl, radiation measurement in the USSR belonged to civil defence: the DP-5, a field radiometer with a needle and six subranges up to 200 r/h, taught on illustrated boards like the ones printed in Kyiv in 1977.
After the accident came household dosimeters, sold widely from 1990 according to Polenov's 1991 handbook. One of our Pripyats still has its price on the back: 175 roubles, when the average Soviet monthly wage was 190.1 roubles in 1985. The Bella was made by Tenzor in Dubna, and two of ours were made in 1992 by Elektron in Zhovti Vody, so production went on after 1991. The RKSB-104 came from Belvar in Minsk.
The article tells that story, shows the instruments and the civil defence boards, and has two small interactive tools: how the SBM-20 tube works, and a quiz to read the displays (µSv/h, mR/h, r/h) on the scale of the 1991 handbook.
https://sovietinparis.com/en/histoire-propagande/compteur-geiger-sovietique-dosimetre-pripiat-bella-rksb-104/
Disclosure: I run a small shop of Soviet items in Paris, the article is on our site.