Measuring device for facilitating the electrical measurement of a substance

摘要

A measuring device for facilitating the electro-chemical measurement of a substance such as a gas comprises a holder ring which has an opening therethrough with an inwardly extending annular resilient sealing lip extending into the opening and an end face with an inner annular projecting portion defining a fitting strip and an outer annular projecting portion spaced radially outwardly from the inner annular portion. A membrane is engaged over the opening and the inner annular projecting portion and its periphery rests in a space between the inner and outer projecting portions. A tightening ring is engaged with the hole of the ring and it includes an end face with an annular groove which is positionable over the inner annular projection of the holder ring. The tightening ring includes an inner annular counter ring part engageable over the membrane and against the sealing lip of the holder ring. It also includes an outer annular part disposed between the inner annular projecting portion and the outer annular projection of the holder ring. The groove of the tightening ring defines an electrolytic receiving space overlying the membrane. The inner annular counterring part of the tightening ring and the sealing lip of the holder ring define with the membrane a releasable seal for the electrolyte in this electrolyte sealing space. The measuring device also includes a body having a central projecting part which contains two electrodes in spaced apart insulated relationship which engage against the membrane. The projecting part deflects the sealing lip of the holding ring to release this electrolyte seal and to permit the electrolyte to flow over the membrane to the electrodes.