초록 ▼

A vapor recovery system is disclosed that utilizes a crystal oscillator for sensing the presence of hydrocarbon in the vapor emissions emanating from a fuel tank during refueling. The crystal oscillator is coated with a layer of material having a sensitivity for hydrocarbon. In response to any inter

A vapor recovery system is disclosed that utilizes a crystal oscillator for sensing the presence of hydrocarbon in the vapor emissions emanating from a fuel tank during refueling. The crystal oscillator is coated with a layer of material having a sensitivity for hydrocarbon. In response to any interaction between the coating layer and hydrocarbon, the crystal oscillator experiences a shift in its oscillation frequency relative to the fundamental resonance frequency. The frequency shift is representative of the hydrocarbon concentration in the vapor emissions. A control signal based on the frequency shift is generated and then used to adjust the operating speed of the vapor pump.

대표청구항 ▼

[ What is claimed is:] [14.] A system for detecting vapor emissions including hydrocarbon emanating from a fuel receiving tank, comprising:vapor collection means for controllably collecting vapor emissions emanating from said fuel receiving tank;vapor monitoring means, disposed for exposure to said

[ What is claimed is:] [14.] A system for detecting vapor emissions including hydrocarbon emanating from a fuel receiving tank, comprising:vapor collection means for controllably collecting vapor emissions emanating from said fuel receiving tank;vapor monitoring means, disposed for exposure to said vapor emissions and including an oscillation means comprising a resonant structure having a contact layer formed thereon and capable of interacting with hydrocarbon, for sensing said vapor emissions and for providing an oscillatory signal generated by said resonant structure and characterized by a frequency of oscillation defining a shift from a fundamental resonance frequency and indicating the hydrocarbon concentration in said sensed vapor emissions; andcontroller means, operatively coupled to said vapor collection means and responsive to the oscillatory signal provided by said vapor monitoring means, for variably controlling the collection of vapor emissions by said vapor collection means in accordance with the frequency shift defined by the oscillation frequency of said oscillatory signal.