Sensor continuously measuring the dielectric constant of a flowing fluid mixture, to determine composition fed to dual fuel engine, has electrodes mounted on outer surface of electrically insulating tube through which fuel flows

摘要

The sensor comprises an insulating tube (12) through which the fuel mixture flows, with two semicircular electrodes (11) arranged along its exterior and thus not in contact with the fluid. The intrinsic sensor capacitance is measured with the aid of two reference electrodes on a portion of the tube separate from the fluid path, so that the dielectric constant of the fluid itself may be accurately determined. Preferably an additional floating electrode is formed on the interior of the tube to raise the capacitance to be measured and hence reduce the demands on the signal processing circuitry.