On-Line Heavy-Water Monitors Based on the Absorption of Infrared Energy

Two types of infrared heavy-water monitors, designed for on-line use at CANDU nuclear power stations and at heavy-water production plants, are described. These monitors are capable of measuring excess concentrations of D2O in H2O (or H2O in D2O) to a few parts per million. Problems associated with changes in environmental conditions, such as temperature and water purity, are discussed, together with methods used to reduce the effects of these changes.