GB1347895A - Electrolytic timers - Google Patents

Abstract

1347895 Elapsed time indicators JAPAN RADIO CO Ltd 19 April 1971 [31 March 1970 9 Nov 1970] 25791/71 Heading G3T An electrolytic elapsed time indicator comprises an anode formed by welding together metallic elements 2 and 1, and a cathode 4 housed in an envelope 5 (of glass or an organic macro-molecular material e.g. polyethylene) containing an electrolytic solution. The electrolysis of the anode element 2 precedes that of anode element 1. Thus when the electrolysis of element 2 is completed at the end of a predetermined elapsed time, electrolysis of element 1 begins and produces a colour change in the electrolyte and proceeds until the electrolyte is saturated with colour changing metal complex ions. The electrolyte may contain a ligand in the form of a salt of the metal of element 2 to produce a deep colouring of the elctrolyte by reacting with metal ions produced in the electrolyte during the electrolysis of the colour changing anode element 1. Alternatively, in a 2nd embodiment, the main constituent of the electrolyte is a salt of the metal of element 2 e.g. zinc sulphate and a discolouring agent (e.g. salicylic acid or nitrose-R-salt) may be added, which agent reacts with the metal ions of the colouring anode element 1. A bubble 9 of air at 1 atm. or gas such as nitrogen, or foamed polystyrene, serves to inhibit increase in internal pressure of the envelope. Constituents of 1st embodiment: - Anode element 2 - cadmium, " " 1 - cobalt, Cathode element 4 - silver plated nickel wire, Electrolyte - ammonium thiocynate, cadmium oxide, water and auxochromic agent such as acetone, methanol, ethanol or ether to promote colouring. Constituents of 2nd embodiment: - Anode element 2 - zinc " " 1 - cobalt Cathode element 4 - nickel Electrolyte - zinc sulphate, magnesium sulphate, aluminium sulphate, boric acid, water & discolouring agent nitrose R salt. The time measuring anode element 2 may alternatively be of tin, iron, nickel or copper and the colouring anode element 1 may be copper, silver iron or manganese.