Isothermal, isobaric, elevated temperature, high-pressure, flow calorimeter

An isothermal, isobaric, flow calorimeter suitable for measuring either endothermic or exothermic heats of mixing from 273 to 423 K and from 0.1 to 40.5 MPa is described. Energy effects from 0.15 to 30 J/min can be measured to an accuracy of ±0.5% for standard test systems at a constant temperature through the use of an automatically controlled heater and a constant cooling Peltier device. The calorimeter was tested by measuring the heat of mixing of water-ethanol at 383 K and 1 MPa and was found to produce data in good agreement with published literature values.