The Detection of Sulfur Dioxide Utilizing a Piezo-Electric Crystal Coated with Ethylenedinitrilotetraethanol

A considerable number of compounds have been shown to be sensitive to sulfur dioxide sorption using quartz crystals. To utilize the technique for the continuous measurement of SO2, coating loss has been shown to be a major limitation. For such a continuously flowing system a previous coating, triethanolamine, was found to evaporate at undesirable rates when used at high enough temperatures and flow rates for an adequate response time. Methods of remedying this problem have led to a new SO2 sensitive coating, ethylenedinitrilotetraethanol. This work presents the technique of coating application, the sensitivity relative to the amount of coating applied, a comparison of totally coated crystals to center coated ones, and a comparison of the new coating relative to the previously used triethanolamine.