Device and method for determining the thermal conductivity and concentration of liquid mixtures

摘要

The device for ascertaining the thermal conductivity and/or a concentration of a mixture (11) consisting of first and second liquid components having different thermal conductivities has a thin-film resistor (23) which is arranged within the mixture (11). This thin-film resistor (23) has a temperature-dependent resistance. In order to increase the resistance, the thin-film resistor (23) is supplied with a current which is in turn limited after a fixed time in order to lower the resistance. The rate of change of the resistance is measured. This measured rate of change corresponds to the thermal conductivity of the mixture (11) and therefore also to the concentration of the first liquid component. The rate of change is converted into a value which shows the thermal conductivity and/or the concentration of the first liquid component of the mixture (11). <IMAGE>