Measuring system for determining mixture ratio of blended fuels

摘要

A fuel mixture measuring system for blended fuels has high accuracy and its stability is independent of the electrical conductivity of the fuels. The equipment comprises a sensor section (A) which determines the electrostatic capacity of the fuel mixture and forms the capacitive branch (1) of a parallel LC resonant circuit in conjunction with an electrically equivalent coil (2). A voltage controlled oscillator (10) generates an HF signal and a phase comparator (5) establishes the phase difference between voltage and current in the sensor section (A) and from the dielectric constant and conductivity of the fuel mixture its mixing ratio is derived (12).