VEB Mantissa welding IHZ-ZIS Abkühlzeit slide rule case 1977 GDR Germany

This bicolor full plastic slide rule comes in its original matching turquoise vinyl sleeve. It is the “Abkühlzeit” or in English the “cool-down-time” slide rule used in welding. It was made by VEB Mantissa from the GDR/DDR (Eastern Germany) in 1977 especially for the Welding school, the ZIS (Zentralinstitut für Schweißtechnik) in Halle an der Saale, Germany. So there will not be to many around anymore (also because plastic and heat is a bad match).  There are indication for different types of steel as well as different types of welding on the front, combined with A-D standard scales. On the back there are indication for the thickness, temperatures and amount of CO2 used in the welding process. It has the standard, well made VEB Mantissa (Reiss) period cursor. It measures ca 33 cm or 13 inches. It is in very good condition with minimal signed of age and use. Do check the attached video on how to work your vintage man tool : slide rule operation instructions!