Electrochemical integrator e.g. for monitoring engine oil condition - has coaxial tubular copper electrodes, inner anode having aluminium core which oxidises to stop current when exposed

摘要

Soluble anode electrolytic cell used as an electrochemical integrator has an anode in the form of a copper tube pressed on to an aluminium rod. Two discs of insulating material hold a copper tube cathode spaced coaxially about the anode and contain the electrolyte. When the Cu of the anode is transferred by electrolysis to the cathode, the aluminium rod becomes exposed and oxidises in the electrolyte to form an insulating layer which blocks further current flow. A current amplifier may be arranged so that the current through the cell is diverted through the amplifier when the anode oxidation blocks current flow, the output of the amplifier being used to signal e.g. a warning. Integrator can be used to monitor engine oil condition, the current flowing through it being the sum of currents indicating such parameters as oil temp., engine speed, oil level and the use of the starter, each current being proportional to the influence on engine oil deterioration of the parameter it indicates. The thickness of the anode is chosen according to the type of oil. When the oil use is sufficient to cause deterioration, the Al core should become exposed and oxidised, the resultant change in current being detected and used to signal a warning. This has application esp. in fleets of vehicles, controlling maintenance. The integrator operates more reliably than known types because the anode contact is firmly maintained, and the design permits higher voltages than the 12-15V limit for the known types.