The True Heat Flow Principle

The CPA202 from ChemiSens works on a unique principal called “True Heat Flow” that makes the CPA202 significantly different from an ordinary heat flow calorimeter. In the CPA202 the heat flow from the reaction process is directly measured using a constant area thermopile comprising hundreds of temperature sensors. This “True Heat Flow transducer” is pre-calibrated at the factory – no additional calibrations are required. All of the heat flow occurs at the well defined bottom of the reactor (the rest of the reactor being insulated). Unlike a conventional reaction calorimeter, the measured heat flow is not sensitive to changes in heat transfer coefficient or wetted heat transfer area. Also, there is no error introduced by asymmetry in the liquid surface (say due to vortex distortion by instrument probes). This means that accurate measurement of evolved (or consumed) power is directly available online without any tedious calibration or post processing.

The temperature of the process reactants is controlled using a sophisticated Peltier element which acts as a reversible heat pump to transfer heat to (or from) the thermostating liquid that is maintained at the same temperature as the process reactants. The True Heat Flow transducer is sandwiched between the Peltier element and the bottom of the reactor vessel.

The thermostatic bath provides a large controlled heat sink for thermal stability and safety.