A circuit arrangement for detecting a load current through a load includes a main transistor, a sensing transistor through which a load current flows that is a measure of the load current flowing through the main transistor. The booting method includes the following steps. In preferred embodiments, a reaction chamber is used that has a cross section perpendicular to the flow of reactant having a dimension along a major axis greater than a dimension along a minor axis. In exemplary method, a target depth for measurement is selected. Annular finger rings constructed from these materials may have a white appearance similar to white gold or platinum, may have increased resistance to scratching compared to traditional cobalt chromium rings, and may be easily be removed by cracking in an emergency situation. The flow meter transmits a signal to the control panel, which is converted to a corrected flow rate signal in response to a fixed value vaporization correction factor.