Differential infrared pyrometry for determination of microkelvin temperature variations.

Abstract

Precise measurement of temperature is significant to studies in chemical and biological systems as their reaction kinetics are sensitive to temperature variations. However, using conventional temperature probes will invade the systems vulnerable to exogenous disturbance, and thus introduce artifacts. Infrared pyrometry is a noninvasive technique for temperature measurement. However, the challenge of current infrared pyrometers is the low sensitivity to small temperature variations that could provide diagnostic information. Here we report a sensitive differential infrared pyrometer based on the spatial modulation achieved by a resonant mirror, which enables a sensitivity to temperature variations on the microkelvin scale. The instrument is employed to monitor the minuscule heat evolution in an acid-base reaction and the decomposition of H2O2 by bovine liver catalase. The instrument holds great promise for monitoring the dynamics of heat evolution in a range of chemical and biological systems in a completely noninvasive manner.