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RECEIVED for review February 27, 1980. Accepted August 25, 1980. The authors are grateful to the Australian government for the award of a Commonwealth Plan Fellowship to P.S.
Electrochemical Determination of Hydrogen Dissolved in Transformer Oil G. Belanger" and G. Missout Insfifutde
Recherche d'Hydro-Qu.4bec, Varennes, Qugbec, Canada
An automatic instrument to determine the hydrogen concentration in an oil (3-5 mL) sample is described. The calibration of the instrument is performed by the injection of a sample prepared in a glass ampule. By presaturaturation of the oil sample before sealing it and use of a 2:l ratio for the volume of the ampule relative to the oil, reproducibility of better than 3% is obtained from ampule to ampule in a given batch (13 ampules prepared per batch). The reproducibility of the determination is of the order of f2% for oil samples above 300 ppm (v/v). Due to the white noise of the electronic circuit (f2 ppm), the standard deviation at lower concentrations increases up to &lo%. The response dgnai is linear to within f10% error from 200 to 15000 ppm as determined from the least-squares analysis of the data. To improve the precision for the lower limit, we used a singlepolnl calibration technique whereby the higher limit (
