| 摘要 |
Apparatus for detecting the presence of gaseous analytes in water comprises a submersible housing 10 enclosing a waterproof sensing chamber 20 having a wall 22 made of material transparent to UV light from source 12 and a wall 18 of a gas permeable membrane for admitting into the chamber gas dissolved in water in which the housing is immersed, first and a second spaced sensing electrodes 24, 26 within the chamber, and a circuit connected to the electrodes for measuring current flowing through the sensing electrodes from ionisation of a gas in the chamber by UV light, characterised in that a third electrode 28 is in the sensing chamber and the circuit applies a sufficient voltage across the third electrode and the first sensing electrode 24 to reduce condensation within the sensing chamber by hydrolysing condensation in electrical contact with the first and third electrodes. |
