Particle analyzing apparatus including a system for visually displaying a particle size distribution curve on a 100 percent scale irrespective of the quantity of particles sampled by the apparatus

Claim 2

In a method for presenting a visual display of particle size distribution and the integral thereof including the steps of passing a given amount of sample containing a plurality of particles through a sensing zone, generating a particle pulse for each particle sensed, each particle pulse having an amplitude related to the size of the particle sensed, segregating the particle pulses into a predetermined number of pulse amplitude ranges, generating in each range an output pulse for each particle pulse having an amplitude falling in that range, separately accumulating the output pulses in each range to obtain a plurality of signal levels each being indicative of the number or quantity of particles in a given size range, cyclically applying the signal levels in a timed sequence to a visual display device to present thereon a particle size distribution curve, and cyclically, sequentially and in cumulative timed steps applying the signal levels to the visual display device to present thereon an integral curve of the particle size distribution curve, the last two steps being repeatedly performed while output pulses are being accumulated, the improvement comprising the steps of cyclically and automatically adjusting the maximum amplitude of the integral curve with respect to a reference voltage related to the maximum voltage to be displayed on the visual display device for a given setting thereof.

Claim 3

The method as claimed in claim 1 wherein said step of adjusting the maximum amplitude of the integral curve includes the steps of comparing the maximum amplitude of the integral of the signal levels with the reference voltage, producing a difference signal equal to the difference between said maximum amplitude and said reference voltage and feeding the difference signal to an attenuating circuit to produce a signal which is applied to the visual display device and which has a maximum amplitude substantially equal to said reference voltage when all of the signal levels are being applied to said attenuating circuit.

Claim 4

The method as claimed in claim 2 wherein said difference signal is used to alter the resistance of a voltage variable resistor in the attenuating circuit.

Claim 5

In a particle size analyzing apparatus including a particle sensor which produces a particle pulse upon sensing a particle in a given amount of sample when the particle is in a sensing zone, the amplitude of each particle pulse being related to the size of the particle sensed, a plurality of particle pulse amplitude discrIminators for sensing particle pulses within predetermined pulse amplitude ranges related to given particle size ranges and for producing an output pulse having a predetermined amplitude for each particle pulse sensed within one of said amplitude ranges, means for separately accumulating the output pulses from each discriminator, an output channel connected to each accumulator, a visual display device, and an electronic switching device for sequentially, alternately and cyclically connecting each of said output channels to said visual display device for presenting on the device the accumulator output signal levels appearing on said channels in spaced relationship thereby tracing on said visual display device a particle size distribution curve for the given amount of sample, said switching device also being operable to connect said output channels sequentially, cyclically and in timed steps to the visual display device to trace thereon an integral curve of the particle size distribution curve, the improvement comprising a gain control apparatus connected between said switching device and said visual display device and including a source of reference voltage related to the maximum voltage to be displayed on the visual display device for a given setting thereof, an attenuating circuit, and means for comparing the reference voltage with an integral signal equal to the sum of the signal levels on all of the output channels, for producing a difference signal equal to the difference between this sum and said reference voltage, and for feeding said difference signals to said attenuating circuit for causing said attenuating circuit to attenuate said integral signal to a signal having a maximum amplitude substantially equal to said reference voltage.

Claim 6

In a particle size analyzing apparatus including a particle sensor which produces a particle pulse upon sensing a particle in a given amount of sample when the particle is in a sensing zone, the amplitude of each particle pulse being related to the size of the particle sensed, a plurality of particle pulse amplitude discrIminators for sensing particle pulses within predetermined pulse amplitude ranges related to given particle size ranges and for producing an output pulse having a predetermined amplitude for each particle pulse sensed within one of said amplitude ranges, means for separately accumulating the output pulses from each discriminator, an output channel connected to each accumulator, a visual display device, and an electronic switching device for sequentially, alternately and cyclically connecting each of said output channels to said visual display device for presenting on the device the accumulator output signal levels appearing on said channels in spaced relationship thereby tracing on said visual display device a particle size distribution curve for the given amount of sample, said switching device also being operable to connect said output channels sequentially, cyclically and in timed steps to the visual display device to trace thereon an integral curve of the particle size distribution curve, the improvement comprising a gain control apparatus connected between said switching device and said visual display device and including a source of reference voltage related to the maximum voltage to be displayed on the visual display device for a given setting thereof, an attenuating circuit, and means for comparing the reference voltage with an integral signal equal to the sum of the signal levels on all of the output channels, for producing a difference signal equal to the difference between this sum and said reference voltage, and for feeding said difference signals to said attenuating circuit for causing said attenuating circuit to attenuate said integral signal to a signal having a maximum amplitude substantially equal to said reference voltage.

Claim 7

In an apparatus for analyzing particles, the improvement comprising, a system for displaying particle size distribution on a 100 percent scale on a visual display device irrespective of the quantity of particles analyzed, the number of particles in different size ranges, so far analyzed at any point in time, being represented by signal levels in diverse signal channels in the particle analyzing apparatus, the signal level in each channel at any time being related to the amount of particles of one size analyzed up to that point in time, the visual display being a comparison of the signal levels representing the number of particles in each size range and such visual display can take the form of a particle size distribution curve or an integral curve thereof, said system including a source of reference voltage related to the maximum voltage to be displayed on the visual display device for a given setting thereof, an amplifier having an output connected to the visual display device, means for selectively connecting the signal channels to an input of said amplifier, means connected between the output of said amplifier and a circuit junction of said amplifier for comparing the reference voltage with the output of said amplifier when all of the signal channels are connected to the input of said amplifier, for producing a difference signal equal to the difference between that output of the amplifier and said reference voltage and means for utilizing said difference signal to attenuate the input to said amplifier whereby said amplifier produces an output signal having a maximum amplitude substantially equal to said reference voltage when all of the signal channels are connected to the input of the amplifier.

Claim 8

In an apparatus for analyzing particles, the improvement comprising, a system for displaying particle size distribution on a 100 percent scale on a visual display device irrespective of the quantity of particles analyzed, the number of particles in different size ranges, so far analyzed at any point in time, being represented by signal levels in diverse signal channels in the particle analyzing apparatus, the signal level in each channel at any time being related to the amount of particles of one size analyzed up to that point in time, the visual display being a comparison of the signal levels representing the number of particles in each size range and such visual display can take the form of a particle size distribution curve or an integral curve thereof, said system including a source of reference voltage related to the maximum voltage to be displayed on the visual display device for a given setting thereof, an amplifier having an output connected to the visual display device, means for selectively connecting the signal channels to an input of said amplifier, means connected between the output of said amplifier and a circuit junction of said amplifier for comparing the reference voltage with the output of said amplifier when all of the signal channels are connected to the input of said amplifier, for producing a difference signal equal to the difference between that output of the amplifier and said reference voltage and means for utilizing said difference signal to attenuate the input to said amplifier whereby said amplifier produces an output signal having a maximum amplitude substantially equal to said reference voltage when all of the signal channels are connected to the input of the amplifier.

Claim 9

In a particle analyzing apparatus including means for generating a signal for each particle sensed in a sensing zone, each signal being related to the size of the particle sensed, means for accumulating signals for particles falling in different size ranges and a visual display device for displaying signal levels in the various accumulating means, the improvement comprising a system for adjusting the signal level received from each accumulating means before the signal level is displayed on the visual display device, said systEm being connected between the accumulating means and the visual display device and including means for cyclically and automatically adjusting the amplitude of the sum of the signal levels with respect to a reference voltage related to the maximum voltage to be displayed on the visual display device for a given setting thereof whereby for the sum of the signal levels said system cyclically produces an output signal having a maximum amplitude substantially equal to the reference voltage during the analyzing of a fluid sample containing particles and for any aliquot thereof.

Claim 10

In a particle analyzing apparatus including means for generating a signal for each particle sensed in a sensing zone, each signal being related to the size of the particle sensed, means for accumulating signals for particles falling in different size ranges and a visual display device for displaying signal levels in the various accumulating means, the improvement comprising a system for adjusting the signal level received from each accumulating means before the signal level is displayed on the visual display device, said systEm being connected between the accumulating means and the visual display device and including means for cyclically and automatically adjusting the amplitude of the sum of the signal levels with respect to a reference voltage related to the maximum voltage to be displayed on the visual display device for a given setting thereof whereby for the sum of the signal levels said system cyclically produces an output signal having a maximum amplitude substantially equal to the reference voltage during the analyzing of a fluid sample containing particles and for any aliquot thereof.

Claim 11

The system as claimed in claim 6 wherein said means for adjusting the amplitude of the signal level includes a source of reference voltage related to the maximum voltage to be displayed on the visual display device for a given setting thereof, means for comparing the reference voltage with the amplitude of a signal in said system related to the sum of the signal levels and for producing a difference signal equal to the difference between the system signal and said reference voltage and means for utilizing said difference signal to attenuate the system signal whereby said system produces for the sum of the signal levels an output signal having a maximum amplitude substantially equal to said reference voltage.

Claim 12

The system as claimed in claim 7 wherein said comparing means includes a comparator having one input connected to the output of said system, one input connected to said source of reference voltage and an output where said difference signal appears.

Claim 13

The system as claimed in claim 8 wherein said means for utilizing said difference signal includes an attenuation circuit comprising a voltage variable resistor and said comparing means is connected to said voltage variable resistor.

Claim 14

The system as claimed in claim 9 wherein said voltage variable resistor is a field-effect transistor having its gate connected to the output of said comparing means.

Claim 15

The system as claimed in claim 7 including an electronically controlled switch having a first terminal connected to the output of said comparing means and a second terminal connected to said means for utilizing said difference signal to attenuate the input signal levels received from the accumulating means said switch being operated by an electronic timer which closes said switch at the same time the timer simultaneously connects all of the signal levels in the accumulating means to said system whereby said system is only operated to adjust the output of said system when a maximum input signal is applied to said system.

Claim 16

The system as claimed in claim 11 wherein said means for utilizing said difference signal includes an attenuation circuit including a voltage variable resistor and said second terminal of said switch is connected to a gate of said voltage variable resistor.

Claim 17

The system as claimed in claim 11 wherein said comparing means includes a memory device, connected to said second terminal of said switch, for storing said difference signal and for applying the same to said means for utilizing said difference signal during the time said switch is open and until a new difference signal is produced upon a subsequent closing of said switch.

Claim 18

The system as claimed in claim 13 wherein said memory device is a capacitor.

Claim 19

The system as claimed in claim 7 including an input resistor connected to the output of the accumulating means.

Claim 20

The system as claimed in claim 7 including an amplifier connected between the accumulating means and the visual display device.

Claim 21

The system as claimed in claim 9 including an amplifier connected between the accumulating means and the visual display device, said attenuation circuit being connected to an input of said amplifier.

Claim 22

The system as claimed in claim 9 including a zero offset circuit connected between the output of said system and said voltage variable resistor.

Claim 23

The system as claimed in claim 10 including a zero offset circuit connected between tHe output of said system and the source terminal of said field-effect transistor.

Claim 24

The system as claimed in claim 16 wherein said means for utilizing said difference signal includes a gain control circuit for said amplifier, said gain control circuit including two resistors connected in series between the output of said amplifier and the common potential for said system, one of said resistors being a voltage variable resistor and said comparing means being connected to said voltage variable resistor.

Claim 25

The system as claimed in claim 20 including a zero offset circuit connected from the output of said system to both an input of said amplifier and the junction between said two resistors.

Claim 26

The system as claimed in claim 7 including a ladder attenuator connected between the accumulating means and the visual display device, an up/down counter having an output connected to said ladder attenuator and having two logic inputs for controlling the up attenuation signal or the down attenuation signal applied by said counter to said attenuator, said comparing means being connected to one input of said counter for applying said difference signal thereto, and gate means for applying clock pulses for predetermined times to the second input of said counter whereby the input to said system can be digitally attenuated in steps when a difference signal is applied to said one input.

Claim 27

The system as claimed in claim 22 including an amplifier connected between said ladder attenuator and said visual display device, said comparing means being connected between the output of said amplifier and said up/down counter.