Particle detection apparatus using fixed frequency oscillator coupled to resonant circuit

Claim 1

APPARATUS FOR THE DETECTION OF PARTICLES IN A FLUID COMPRISING, IN COMBINATION, A FLUID TRANSFER PIPE, A CAPACITIVE SENSOR WITHIN SAID PIPE, SAID FLUID SERVING AS THE DIELECTRIC OF SAID CAPACITIVE SENSOR, AN INDUCTANCECAPACITANCE CIRCUIT, SAID INDUCTANCE-CAPACITANCE CIRCUIT INCLUDING SAID CAPACITIVE SENSOR CONNECTED IN PARALLEL WITH AN INDUCTOR, SAID INDUCTANCE-CAPACITANCE CIRCUIT HAVING A RESONANT FREQUENCY, A FIXED FREQUENCY OSCILLATOR FOR PRODUCING AN ALTERNATING VOLTAGE, THE FREQUENCY OF SAID ALTERNATING VOLTAGE BEING DIFFERENT FROM THE RESONANT FREQUENCY OF SID INDUCTANCE-CAPACITANCE CIRCUIT, MEANS CONNECTING THE ALTERNATING VOLTAGE PRODUCED BY SAID OSCILLATOR TO SAID INDUCTANCE-CAPACITANCE CIRCUIT, A PEAK DETECTOR HAVING INPUT AND OUTPUT TERMINALS FOR PROVIDING A VOLTAGE VARYING IN ACCORDANCE WITH THE AMPLITUDE ENVELPOE OF SIGNALS AT SAID OSCILLATOR FREQUENCY SUPPLIED THERETO, MEANS CONNECTING SAID INDUCTANCE-CAPACITANCE CIRCUIT IN PARALLEL ACROSS THE INPUT TERMINALS OF SAID PEAK DETECTOR, A PULSE AMPLIFIER HAVING INPUT AND OUTPUT TERMINALS, MEANS CONNECTING THE OUTPUT TERMINALS OF SAID PEAK DETECTOR TO THE INPUT TERMINAL TO SAID PULSE AMPLIFIER, PULSE-OPERATED DISPLAY MEANS, AND MEANS CONNECTING THE OUTPUT TERMINAL OF SAID PULSE AMPLIFIER TO SAID PULSEOPERATED DISPLAY MEANS.