Dr. Morris et al., Nonisothermal electrochemical cell for monitoring hydrogen or oxygen in high temperature water, J APPL ELEC, 29(8), 1999, pp. 971-977
A nonisothermal, solid state electrochemical sensor for monitoring hydrogen
or oxygen dissolved in high temperature (to about 500 K) water is describe
d. Nafion(R) in the form of tube was used as the electrolyte. The reference
electrode at ambient temperature and pressure was a saturated aqueous solu
tion of Fe2+ and Fe3+ sulphates. Sensor voltage measurements with dissolved
hydrogen showed good reproducibility and long term stability. A regression
equation for the hydrogen concentration related to cell voltage and water
temperature was derived. Sensor voltage measurements with dissolved oxygen
showed relatively poor reproducibility and long term stability. This is att
ributed to the greater complexity of electrode reactions involving oxygen a
nd water.