The principle of the pentoxide phosphorous dew point meter.

Principle of the TMA series continuous moisture analyzer for corrosive gases.

The principle of pentoxide phosphoric acid (electrolytic) moisture analysis is utilized. (1) Phosphoric acid generates phosphorus pentoxide, hydrogen, and oxygen through electrolysis. 4H3PO4 → 2P2O5 + 6H2 + 3O2 (2) Phosphorus pentoxide absorbs water. 2P2O5 → 6H2O + 4H3PO4 The sensor is made of glass, with platinum electrodes (rhodium as an option) wound in a spiral around it. Oxygen is generated between the electrodes. The amount of water absorbed by the generated phosphorus pentoxide balances with the amount of hydrogen and oxygen produced, allowing for moisture measurement based on Faraday's law (the amount of substance electrolyzed is proportional to the amount of electric charge passed). It is resistant to corrosion, making it suitable for measuring moisture in corrosive gas environments. Additionally, it is a long-established dew point meter. For more details on the principle of the phosphorus pentoxide dew point meter, please refer to the URL below.

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