Steve R. Domen

Steve R. Domen developed physical water calorimetry methods at the National Institute of Standards and Technology. His 1994 sealed-water instrument measured absorbed dose from a minute radiation-induced temperature rise, while investigating how dissolved gases change the fraction of deposited energy that appears as heat.^[ref]

The apparatus enclosed water in a thin glass vessel immersed in a larger water tank. Two calibrated thermistors in glass capillaries formed part of a Wheatstone bridge that detected the temperature response. The vessel also limited convection. Comparing different dissolved-gas conditions tested the heat defect, rather than assuming that all absorbed energy immediately becomes heat.^[ref]

For an original ideal calculation, neglect the heat defect and heat transfer during a reading. With water specific heat capacity $c_p=4180\mathrm{J}\mathrm{k}{\mathrm{g}}^{-1}{\mathrm{K}}^{-1}$ and measured rise $\Delta T=0.240\mathrm{mK}$,This illustrates why sub-millikelvin thermometry matters. It is not a reported run: the real measurement model must include the instrument's corrections and measurement uncertainty.