Archive of Collections

Details and Image

TypeModel No.MakerCountryConstruction
DateScale LengthArea of Use
Tervakoski Slide Rule
Blundell Harling Ltd.England
est. 1960's5.4 cm x 35 cmElectrical Calculations

Notes: "1) The Tervakoski slide rule was ordered by a company making components for electrical capacitors 2) Several complicated scales are believed to be used for power factor correction on power lines 3) Power factor correction corrects for inductive loads (motors) to reduce wire conductor size 4) See ""Tervakoski Rule"" by Colin Barnes, UKSRG Gazette, 16, 2015."

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