In the photomicrocalorimetric module designed by Johansson and Wadsö for a commercial Thermometric TAM heat conduction batch
microcalorimeter, the incident light from an external xenon lamp was divided by a beam splitter and directed to the two vessels
of the differential system by light guides ideally to give zero heat flow. In practice this proved difficult and so to improve
the balance between the vessels in terms of the incident light heat output as well as potentially to give more versatility
regarding the choice of wavelengths, the xenon lamp-based system was replaced in the first stage by a pair of cold white LEDs
embedded directly in the test and reference vessels. The LEDs had independent electrical circuits to achieve the balance by
manual adjustment. As a second stage, the test vessel was equipped with PTFE tubing for changing the liquid phase in it while
it was in the middle thermal equilibrium position. This improved the reproducibility of the results.
Authors:J. J. Joyal, L. D. Hansen, D. R. Coons, G. M. Booth, B. N. Smith, and D. D. Mill
Heat and CO2rates are measured on M. domesticapupae as a function of age and temperature. Heats of combustion of flies, pupae, and puparia are also measured. Heat and CO2rates decrease for 3 d post-pupation and increase exponentially over 4 d prior to eclosure. Heat and CO2rates are low and increase slowly from 5 to 23C, then rapidly increase from 23 to 26C, then more slowly up to 38C where
pupae are stressed. Respiratory substrate varies with age and temperature, is a mix of lipids and carbohydrates, and has an
average carbon oxidation state of -0.3 at room temperature. Humidity, elevated CO2, or reduced O2did not affect pupal metabolism.
to monitor changes of the rate of metabolically generated heat and to calculate total heat effects in the examined processes. A combination of calorimetric method with respirometric measurements is known as calorespirometry.