Particle study apparatus including an axial trajectory sensor

Claim 2

A particle study apparatus including the combination of an axial trajectory sensor and a particle analyzing apparatus; said particle analyzing apparatus having a detecting zone through which the particles are caused to pass for producing pulses, and said detecting zone having an axis; the particles, when passing closest to an axial trajectory through the detecting zone, producing desirable particle pulses having amplitudes which are most nearly proportional to the respective sizes of the particles, and also thereby having a certain approximate duration, and the particles, when passing through the detecting zone on trajectories displaced from its axis producing other particle pulses having amplitudes which are not necessarily proportional to their respective sizes and having durations which tend to be longer than said certain approximate duration; said axial trajectory sensor being constructed with an input and an output and arranged to respond to said desirable particle pulses in a first manner and to respond to said other particle pulses in a second manner and further comprising means for measuring the duration of at least a predetermined portion of a particle pulse applied to the input of said sensor at some predetermined fraction of the amplitude thereof and deriving a durationmeasUring pulse having the measured duration, means for establishing an electrical standard equivalent to a maximum desired duration for the duration-measuring pulses, means for comparing each said duration-measuring pulse with said standard and for providing a first type of energizing signal if said standard is not exceeded and a second type of energizing signal if said standard is exceeded, and output means coupled to receive said first and second types of energizing signals for generating, respectively, the first and second manners of response.

Claim 3

A particle study apparatus according to claim 1 in which said electrical signals are derived from desirable particle pulses by means of signal forming structure coupled to said sensor input and operable in a manner which produces output pulses of predetermined duration having the respective amplitudes of desirable particle pulses.

Claim 4

A particle study apparatus according to claim 1 in which said means for measuring duration is operative to measure the duration of the entire particle-produced pulse at said predetermined fraction of the amplitude thereof.

Claim 5

A particle study apparatus according to claim 1 in which said measuring means is constructed and arranged to produce an electrical wave having a duration substantially longer than the duration of the particle pulse from which the electrical wave is derived and having a constant amplitude over a substantial portion of its duration, which amplitude is said predetermined fraction of the amplitude of the particle pulse from which it is derived; and said measuring means is constructed for comparing each particle pulse with its said electrical wave during a period of time when the amplitude of said wave is constant.

Claim 6

A particle study apparatus according to claim 1 in which said receiving means includes a gate and a switch, with said gate being connected between said standard establishing means and said switch; a strobe pulse generator being connected to said gate to produce a strobing pulse from said duration-measuring pulse to energize said gate and operate said switch to pass any signal or part thereof for the duration only of said strobing pulse; whereby said second type of energizing signal inhibits operation of said gate to prevent action of said strobing pulse on said switch, and said first type of energizing signal enables said gate.

Claim 7

A particle study apparatus according to claim 1 which includes means providing a pair of fluid bodies, an aperture between the bodies with the bodies being insulated one from the other except through said aperture, one of the fluid bodies comprising a sample suspension of particles, means establishing an electric field in said aperture, means for flowing the sample suspension in the aperture to produce impedance changes in the aperture caused by the passage of said particles, said aperture thereby defining said detecting zone, means for detecting the impedance changes and producing said desirable and said other particle pulses, and means for coupling said detecting means to said sensor input.

Claim 8

A particle study apparatus according to claim 6 in which a pulse height analyzer is coupled to said sensor output and is connected for response to each particle pulse for which said sensor generates said first manner of response.

Claim 9

A particle study apparatus according to claim 1 which includes electrical converting means which is connected to said measuring means and constructed to convert said duration-measuring pulse into a plurality of clock pulses which can be passed for the duration of the duration-measuring pulse; said electrical standard is defined by a preset number of pulses; and said comparing means is constructed to compare the preset number of pulses with the number of pulses passed for the duration of the duration-measuring pulse for generating said first and second types of energyzing signals.

Claim 10

A particle study apparatus according to claim 8 in which said standard establishing means comprises a counter and controls for presetting said counter to respond to said preset number of pulses, said counter being constructed for producing said energizing signal of said first type if the number of pulses passed by said duration-measuring pulse does not exceed said preset number and for producing said second type of energizing signal if the number of pulses passed by said duration-measuring pulse does exceed said preset number.

Claim 11

A particle study apparatus according to claim 8 which includes means providing a pair of fluid bodies, an aperture between the bodies with the bodies being insulated one from the other except through said aperture, one of the fluid bodies comprising a sample suspension of particles, means establishing an electric field in said aperture, means for flowing the sample suspension in the aperture to produce impedance changes in the aperture caused by the passage of said particles, said aperture thereby defining said detecting zone, means for detecting the impedance changes and producing said desirable and said other particle pulses, and means for coupling said detecting means to said sensor input.

Claim 12

A particle study apparatus according to claim 1 which includes electrical converting means which is connected to said measuring means and is constructed to convert said duration-measuring pulse into an electric time-signal pulse having an amplitude; said standard comprises a signal level; and said comparing means is constructed to compare a time-signal pulse against said signal level to generate said first and second types of energizing signals.

Claim 13

A particle study apparatus according to claim 11 in which said converting means comprises an integrator responsive to the duration-measuring pulse, which generates the time-signal pulse as a flat-topped pulse of the ramp-and-pedestal type.

Claim 14

A particle study apparatus according to claim 11 which includes means providing a pair of fluid bodies, an aperture between the bodies with the bodies being insulated one from the other except through said aperture, one of the fluid bodies comprising a sample suspension of particles, means establishing an electric field in said aperture, means for flowing the sample suspension in the aperture to produce impedance changes in the aperture caused by the passage of said particles, said aperture thereby defining said detecting zone, means for detecting the impedance changes and producing said desirable and said other particle pulses, and means for coupling said detecting means to said sensor input.

Claim 15

A particle study apparatus comprising the combination of an axial trajectory sensor and a Coulter type of particle analyzing apparatus said Coulter type of particle analyzing apparatus including means providing a pair of fluid bodies, an aperture between the bodies and the bodies being insulated one from the other except through said aperture, one of the fluid bodies comprising a sample suspension of particles, means establishing an electric field in said aperture, means for flowing the sample suspension in the aperture to produce impedance changes in the aperture caused by the passage of particles, means for detecting the impedance changes and producing said desirable and undesirable particle pulses, and means for coupling said detecting means to an input terminal means of said axial trajectory sensor; particles passing through said aperture producing desirable particle pulses whose amplitudes are most nearly proportional to their respective sizes when passing closest to an axial trajectory through said aperture and having thereby a certain approximate duration, and particles passing through said aperture on trajectories displaced from the axis will produce other particle pulses whose amplitudes are not necessarily proportional to their respective sizes and whose durations tend to be greater than said certain approximate duration; said sensor constructed and arranged to respond to said desirable particle pulses and not to respond to said other pulses and comprising: input terminAl means and output terminal means having a channel for passage of electrical signals between the terminals with switch means in said channel to control the signals which appear at the output terminal means, the input terminal means adapted to have said desirable and other particle pulses applied thereto, means for measuring the duration of at least a predetermined portion of a particle pulse applied to said input terminal means at some predetermined fraction of the amplitude thereof and deriving a duration-measuring pulse of constant amplitude and having the measured duration, means for converting said duration-measuring pulse into an electrical quantity whose value is proportional to the time duration of said duration-measuring pulse, means establishing an electrical effect of a standard equivalent to a maximum desired duration distinguishing between quantities produced by desirable and other pulses, means comparing said quantity with said standard and providing one type of energizing signal if the quantity exceeds the standard and other types of energizing signal if the said quantity does not exceed the standard, and means for applying one of said energizing signals to the switch means in said channel to permit passage to said output terminal means of only electrical signals derived from desirable particle pulses.

Claim 16

A particle study apparatus comprising the combination of an axial trajectory sensor and a Coulter type of particle analyzing apparatus said Coulter type of particle analyzing apparatus including means providing a pair of fluid bodies, an aperture between the bodies and the bodies being insulated one from the other except through said aperture, one of the fluid bodies comprising a sample suspension of particles, means establishing an electric field in said aperture, means for flowing the sample suspension in the aperture to produce impedance changes in the aperture caused by the passage of particles, means for detecting the impedance changes and producing said desirable and undesirable particle pulses, and means for coupling said detecting means to an input terminal means of said axial trajectory sensor; particles passing through said aperture producing desirable particle pulses whose amplitudes are most nearly proportional to their respective sizes when passing closest to an axial trajectory through said aperture and having thereby a certain approximate duration, and particles passing through said aperture on trajectories displaced from the axis will produce other particle pulses whose amplitudes are not necessarily proportional to their respective sizes and whose durations tend to be greater than said certain approximate duration; said sensor constructed and arranged to respond to said desirable particle pulses and not to respond to said other pulses and comprising: input terminAl means and output terminal means having a channel for passage of electrical signals between the terminals with switch means in said channel to control the signals which appear at the output terminal means, the input terminal means adapted to have said desirable and other particle pulses applied thereto, means for measuring the duration of at least a predetermined portion of a particle pulse applied to said input terminal means at some predetermined fraction of the amplitude thereof and deriving a duration-measuring pulse of constant amplitude and having the measured duration, means for converting said duration-measuring pulse into an electrical quantity whose value is proportional to the time duration of said duration-measuring pulse, means establishing an electrical effect of a standard equivalent to a maximum desired duration distinguishing between quantities produced by desirable and other pulses, means comparing said quantity with said standard and providing one type of energizing signal if the quantity exceeds the standard and other types of energizing signal if the said quantity does not exceed the standard, and means for applying one of said energizing signals to the switch means in said channel to permit passage to said output terminal means of only electrical signals derived from desirable particle pulses.