ARISTO-Werke Dennert & Pape, Hamburg / Germany (1961) *********************************************************** S C A L E S of the ARISTO POCKET E L E K T R O Model 852 =========================================================== Front Side [ RED ] Back Side =========================================================== ( 0 ... 13 cm Ruler ) U1/U2 X5 A X2 ----------------------------------------------------------- B X2 Volt 0 .. +100 dB Neper ln|U1/U2| mV 0 .. -100 dB C X mV 0 .. -10 dB ----------------------------------------------------------- [D] [X] [U1/U2] [ 0 .. 20 ] dB 20*lg|U1/U2| R E M A R K S : =========================================================== Production Code = G611 = Geretsried, 1961, Lot 1 Historical Remarks ... This Pocket Slide Rule was a gift from the company » TN « (= TELEFONBAU+NORMALZEIT), well known for their telephones and synchrone time systems. Neper [ N ] = ln( U1 / U2 ) Dezibel [ dB ] = 10*lg( P1 / P2 ) = 10 * lg{ ( U12/R1 ) / ( U22/R2 ) } = 10 * lg{ ( U1 / U2 )2 * R2/R1 } = 20 * lg| U1 / U2 | with R1 = R2 spec.: 0 dB = 1 mW on 600 Ω = 0.775 V ===>> 1 N = 8.686 dB 1 dB = 0.1151 N impressum: *********************************************************** © C.HAMANN http://public.BHT-Berlin.de/hamann 04/30/09 |