Chemical and Microbial Activity Rates Under Square‐Wave and Sinusoidal Temperature Fluctuations

SUMMARY Temperature amplitudes to 160° and Q 10 values from 1 to 30 were integrated to derive coefficients of fluctuation. Multiplication of the coefficient by the reaction rate at the mean temperature permits ready calculation of the average reaction rate when temperature fluctuations assume either a square‐wave or sinusoidal form of cycling. The method is applicable to any temperature scale. Ascorbic acid solutions were less stable when the temperature was cycled from −6 to 30°F than when held steady at 12°F. Aerobacter aerogenes and Staphylococcus aureus cultures incubated under cyclic conditions from 40 to 80°F usually grew quicker than cultures incubated at a constant temperature of 60°F.