Particle analyzer threshold level control

Claim 1

IN COMBINATION: A PARTICLE SCANNING APPARATUS GENERATING A DISCRETE SIGNAL FOR EACH PARTICLE SCANNED, EACH SAID SIGNAL HAVING A PARAMETER WHICH IS A FUNCTION OF A PHYSICAL PROPERTY OF A RESPECTIVE SCANNED PARTICLE, AND A THRESHOLD DETECTOR CIRCUIT COUPLED TO SAID SCANNING APPARATUS AND RECEIVING EACH OF SAID SIGNALS, SAID DETECTOR CIRCUIT HAVING A BIASABLE DETECTOR PORTION COUPLED TO RECEIVE ALL OF SAID SIGNALS, SAID DETECTOR CIRCUIT ALSO HAVING A FIRST AND A SECOND THRESHOLD DETERMINING MEANS COUPLED TO SAID DETECTOR PORTION FOR AT ANY ONE TIME BIASING SAID PORTION BY A THRESHOLD LEVEL DEVELOPED BY EITHER ONE OF SAID THRESHOLD DETERMINING MEANS, SAID FIRST AND SECOND THRESHOLD DETERMINING MEANS BEING ELECTRICALLY PARALLEL TO ONE ANOTHER AND FURTHER COMPRISING, A COMMON POWER SOURCE COUPLED TO THE PARALLEL MEANS, AND SAID DETECTOR PORTION FURTHER HAVING AN OUTPUT FROM WHICH PASSES A RESPONSE ONLY TO EACH SAID SIGNAL HAVING SAID PARAMETER OF SUFFICIENT MAGNITUDE TO OVERRIDE THE BIAS APPLIED TO SAID DETECTOR PORTION BY SAID ONE THRESHOLD MEANS.