“A Robbanás”

Data:

• Linear wooden slide rule with celluloid(?) scales and a paper table on the back
• I guess for nuclear blasts calculation.
• Unknown manufacturer.
• The back of the slide contains an unmarked 500...1000 scale that corresponds to the 0...500 scale on the side of the stock!
• The language on the back side is Hungarian.
• The central picture shows a nuclear explosion on air (left) and on ground (right).
• The table on the right is quite clear: it gives the dimension of the “mushroom” as function of the power (in kilotons).
• The table on the left, for air explosion, gives the conversion from sexagesimal to military degrees (360°=6000).
  Note the rounding-off error for 90°: 1499 v should be 1500 v.
  
• On the front side you can see the scales for calculations.
• No manual/instruction available.

Questions:

1. What do the symbols of the scales mean?
   Google Gemini gives this interpretation:
   Rkm = radius in kilometer (distance from ground zero)
   qkt = kiloton TNT equivalent. The “q” (“quantitás” or “quanti”) is a label for the explosive strength.
   Siegfried Lion
   The α scale is amount of radiation. Meine van Essen
   “t sec” and “x sec” might indicate different times: time-since-explosion and time-spent-in-danger-zone. But the range of these scales is very limited. On the Blundell Radiac, the time scale runs from 10 minutes to 30 weeks! Andries de Man
   “t perc” in the right table on the back means “t minutes”. This is a strange, small time range with little variation. Andries de Man
    
2. How to use the slide rule?
   Compare with the Radiacs and similar devices of various countries. Meine van Essen