LIQUID LEVEL AND COMPOSITION SENSING SYSTEMS AND METHODS.

摘要

An automotive urea solution monitoring device (100) is deployed in conjunction with the urea tank (102) of a selective catalytic reduction vehicle. An RF signal of a constant frequency is generated across a resonant circuit (410), which is comprised of an inductor (411) and a PCB trace capacitor (412). Electromagnetic radiation is propagated into the automotive urea solution in the urea tank. The conductivity and dielectric properties of the liquid change the impedance of the discrete/trace capacitor (412) and or the discrete/trace inductor (411). These changes are proportional to ammonia content, temperature, and/or level of the automotive urea solution in the urea tank and are detected by a microcontroller (401), and then transmitted to a selective catalytic reduction vehicle engine management system.