HISTORIC WRIST WATCH w.Radium Hands & Figures, OLMA / Switzerland (1930) ************************************************************************ This is the stainless steel watch of my father, who was killed in WWII. I got it from my mother as I was 12 year old. I carried it day and night until I was 30 and bought my OMEGA AUTOMATIC in Switzerland. My job in Computer Science & Nuclear Medicine in the University Hospital of Berlin allowed me to measure the RADIOACTIVITY of this watch ... 18.5 nCi Radium-226 ( Half-Decay-Time = 1600 years ) With its "Gamma Constant" Γ = 0.825 [ ( R * m2 ) / ( h * Ci ) ] the EXPOSURE could be calculated: 153 μR/h on my WRIST (= 1 cm distance ) and 3.3 mR/a on my GONADES (= 20 cm distance ) ... Compare it with the "Natural Radioactivity" ~ 110 mR/a for Germany H I S T O R I C A L R E M A R K S : ======================================================================== Paul J. Bourquin was a skilled watch maker. In 1860 he designed a watch and named it "Numa Jeannin" after his son's name. In 1894 his son took over the business and in 1906 he founded the factory NUMA JEANNIN CO. in Fleurier / Switzerland to produce high quality watches under the brand name »OLMA«. Since than, OLMA is on the market for over 100 years. Have a look at the OLMA HomePage ... http://www.olmawatches.com/en/#/history impressum: ************************************************************************ © C.HAMANN http://public.BHT-Berlin.de/hamann 06/28/11 |