Chemical Temperature Integration

The sugar-inversion method (Pallmann method) of deriving mean temperatures related the reaction velocity of sucrose hydrolysis to temperature by means of an Arrhenius-type equation. The method was tested for precision, accuracy and adaptability to climatological networks. Twenty-milliliter glass ampoules filled with a clear sucrose solution were used as temperature sensors. The sensors were virtually unaffected by shortwave radiation. Precision of the method for half-month periods in forested terrain was ±0.02C. Absolute accuracy of the method was severely affected by the nonlinearity of sensor response; this was circumvented by use of empirical corrections based on the temperature mean and amplitude. At five standard climate stations, arithmetic mean temperatures for half-month periods (1967–1968) were predicted with an average error of 0.37–0.64C in summer (over mean temperatures of 30 to 10C) and 0.86–1.05C in winter (over mean temperatures of 10 to −10C). The Pallmann method of temperature integration is simple and economical. With the addition of 150 gm liter−1 sodium chloride to the sucrose solution, the method is usable in all seasons.