The invention relates to a heat exchanger with plate structure, comprising a stack of plates composed of circular heat transfer plates by welding and fitted inside a housing unit used as a pressure vessel, whose periphery is provided with flow guides, by means of which the second heat transfer medium is guided to desired ducts in the stack of plates. The non-olefinic chain transfer agent includes one or more compounds selected from H2, alkylsilanes, alkylalkoxysilanes, alkylgermanes, alkylalkoxygermanes, alkylstannanes, and alkylalkoxystannanes. A determination of whether the data is stored in the queried cache node is made. A subtracter subtracts the first output value multiplied by the first factor from the second output value; and a divider divides the output value of the subtracter by a second factor. The resolution of the system is improved over the resolution that can be attained using a Fabry-Perot resonator. 53 inches; and a cover comprised of a material having a second Shore D hardness at least 10 points less than the first hardness.