International Workshop F

Leo's mystery slide rule Nr. 2

An unknown black disc.

Click images for magnification

disk

Data:

  • Diameter: 98mm
  • Material: Aluminum
  • Front has 1 rotating disc with division from 5 to 50 and a fixed disc with a division from minus 20 to plus 25.
  • A third scale is visible through a small opening with a division from 30 to 150
  • Text on front indicates “correction” , “level” and “25°C”
  • In the middle is a name that is not easily readable and only “C ??BIJ” can be deciphered
    “C ??BIJ” is probably “CORR. BIJ”, indicating "Correction at 25°C" Andries de Man
  • Back side no information or divisions.

Questions:

  1. What is this disk for?
    ChatGPT to the rescue?
    When Siegfried Lion asked ChatGPT to solve this problem this answer was given. Discuss!
  2. How does this disk work?
  3. Can a manufacturer be identified?