Tube for continuous, long-term pH measurement - in liquids of gas permeable, indicator-impermeable material

摘要

For continuous, long-term measurement of pH of liq., e.g. aquarium water, as well as direct or indirect measurement of concn. and concn. changes, a test container in the form of a silicone rubber hose (3), adhesive bonded at one end to close it. Gases are exchanged via the surface (10) of the hose wall (9) and concn. gradient is produced between the water and the test medium within the hose. The wall is impermeable to the indicator substance. Equilibrium is produced beween the CO2 content determining pH in the water and the test medium. ADVANTAGE - Rapid response to changes.