US3810011A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for analyzing the particle volume distribution for a plurality of particles of different size in a quantity of liquid
Assignee: Coulter Electronics Inc
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Filing: 1973-04-18
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Granted: 1974-05-07
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Expires: 1993-04-18
Abstract
Abstract The apparatus and method are utilized for ascertaining the volume of particles within predetermined particle-size ranges from a total amount of particulate matter comprising particles of different size, suspended in a quantity of liquid. The apparatus and method utilize the output signals from a particle analyzing device where the quantity of liquid containing particles of different size is caused to flow through a sensing zone including an electric current path of small dimensions and where each particle sensed generates an electrical signal having an amplitude proportional to the size of the particle sensed. The electrical signal is applied simultaneously to a plurality of comparators and to a pulse stretcher which stores the maximum amplitude of the signal. Each of the comparators is connected to a different threshold level and the output of each comparator is connected to logic signal generating circuitry including trailing edge and leading edge detectors, multivibrators and VETO AND circuits. The output of the pulse stretcher is connected to a plurality of output channels and the output of each VETO AND circuit is connected to an electronic switch in one of the output channels. The logic signal generating circuitry determines within which size range the particle falls and sends a logic signal from one of the AND circuits to one of the electronic switches to close the circuit in that output channel so that the signal from the pulse stretcher can be passed into the output channel. Signal converting circuitry is associated with the output channels for converting the stored maximum amplitude signal in the pulse stretcher to an electrical quantity capable of being accumulated in one of the integrators in one of the output channels. An electrical quantity is produced for each electrical signal generated by each particle sensed and is stored in an integrator in one of the output channels which is determined by the size of the particle. The output signal in each output channel is proportional to the total accumulated electrical quantities in that output channel and hence also proportional to the total volume of particles falling within a particular particle size range.
Inventors
- 👤 W Coulter
- 👤 W Hogg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:34
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/10; G01N15/1031; G01N15/12
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
252 words
A method for ascertaining the volume of particles within predetermined particle-size ranges from a total amount of particulate matter comprising particles of different size suspended in a quantity of liquid, said method comprising the steps of: A. passing the quantity of liquid through a sensing zone where each particle sensed generates an electrical signal having an amplitude which is directly proportional to the size of the individual particle sensed; B. tracking each signal and then storing the maximum amplitude of each electrical signal in an analog signal channel while simultaneously comparing the maximum amplitude with threshold levels to determine the particle-size range within which the particle which generated the electrical signal falls and generating a logic signal for that particle-size range; C. applying the stored maximum amplitude of the electrical signal to a plurality of normally open-circuited output channels; D. utilizing the logic signal to close the circuit in the output channel which is to receive electrical signals for particles within the particle-size range within which the particle falls; E. converting the stored maximum amplitude of the electrical signal into an electrical quantity which is directly related to the amplitude of the signal and which is capable of being accumulated; F. accumulating in each output channel the electrical quantities produced therein; and G. deriving at least one output signal in each output channel which is proportional to the total accumulated electrical quantities in that output channel and hence also proportional to the total volume of particle falling within a particular particle-size range.
Claim 2
Independent Claim
252 words
A method for ascertaining the volume of particles within predetermined particle-size ranges from a total amount of particulate matter comprising particles of different size suspended in a quantity of liquid, said method comprising the steps of: A. passing the quantity of liquid through a sensing zone where each particle sensed generates an electrical signal having an amplitude which is directly proportional to the size of the individual particle sensed; B. tracking each signal and then storing the maximum amplitude of each electrical signal in an analog signal channel while simultaneously comparing the maximum amplitude with threshold levels to determine the particle-size range within which the particle which generated the electrical signal falls and generating a logic signal for that particle-size range; C. applying the stored maximum amplitude of the electrical signal to a plurality of normally open-circuited output channels; D. utilizing the logic signal to close the circuit in the output channel which is to receive electrical signals for particles within the particle-size range within which the particle falls; E. converting the stored maximum amplitude of the electrical signal into an electrical quantity which is directly related to the amplitude of the signal and which is capable of being accumulated; F. accumulating in each output channel the electrical quantities produced therein; and G. deriving at least one output signal in each output channel which is proportional to the total accumulated electrical quantities in that output channel and hence also proportional to the total volume of particle falling within a particular particle-size range.
Claim 3
Dependent Claim
50 words
The method according to claim 1 wherein the signal stored in the alalog signal channel is a voltage signal which is applied to a pump in the close circuited output channel, the output from the pump constituting said electrical quantity and said accumulating being accomplished by integrating said electrical quantities.
Claim 4
Dependent Claim
92 words
The method according to claim 1 wherein the stored signal in the analog signal channel is a voltage signal which is converted to a current signal and the particular channel which is close-circuited to receive said current signal is closed for a predetermined period of time for each electrical signal generated, the electrical quantity generated for each particle being equal to the current signal multiplied by a time constant equal to the predetermined time period, and the electrical quantity is accumulated by integrating the current signal for the predetermined period of time.
Claim 5
Dependent Claim
56 words
The method according to claim 1 wherein the output channels are divided into a plurality of groups and each electrical signal is tracked and stored in a plurality of analog signal channels, one each for each of the groups of output channels, the analog signal in each analog signal channel being multiplied by a sensitivity factor.
Claim 6
Independent Claim
293 words
An apparatus for ascertaining the volume of particles within predetermined particle-size ranges from a total amount of particulate matter comprising particles of different size suspended in a quantity of liquid utilizing the output signals from a particle-analyzing device wherein a quantity of liquid containing particles of different size is caused to flow through a sensing zone including an electric current path of small dimensions and wherein each particle sensed generates an electrical signal having an amplitude proportional to the size of the particle sensed, said apparatus comprising: A. means for tracking each signal and for storing the maximum amplitude of each signal; B. means for simultaneously comparing the maximum amplitude of each signal with a plurality of threshold levels to determine the particle-size range within which the particle which generated the eLectrical signal falls; C. means for generating a logic signal for each particle-size range; D. a plurality of normally open-circuited output channels connected to said signal tracking and storing means; E. switch means in each of said output channels connected to said logic signal-generating means, said logic signal-generating means being operable to apply a logic signal to the switch means in the output channel for the particle-size range within which the particle falls; F. means associated with each output channel for converting the stored maximum amplitude of the electrical signal into an electrical quantity which is directly related to the amplitude of the electrical signal and which is capable of being accumulated; and G. means in each output channel for accumulating the electrical quantities produced therein, the output signal from each accumulating means being proportional to the total accumulated electrical quantities in that particular output channel and hence also proportional to the total volume of particles falling within a particular particle-size range.
Claim 7
Independent Claim
293 words
An apparatus for ascertaining the volume of particles within predetermined particle-size ranges from a total amount of particulate matter comprising particles of different size suspended in a quantity of liquid utilizing the output signals from a particle-analyzing device wherein a quantity of liquid containing particles of different size is caused to flow through a sensing zone including an electric current path of small dimensions and wherein each particle sensed generates an electrical signal having an amplitude proportional to the size of the particle sensed, said apparatus comprising: A. means for tracking each signal and for storing the maximum amplitude of each signal; B. means for simultaneously comparing the maximum amplitude of each signal with a plurality of threshold levels to determine the particle-size range within which the particle which generated the eLectrical signal falls; C. means for generating a logic signal for each particle-size range; D. a plurality of normally open-circuited output channels connected to said signal tracking and storing means; E. switch means in each of said output channels connected to said logic signal-generating means, said logic signal-generating means being operable to apply a logic signal to the switch means in the output channel for the particle-size range within which the particle falls; F. means associated with each output channel for converting the stored maximum amplitude of the electrical signal into an electrical quantity which is directly related to the amplitude of the electrical signal and which is capable of being accumulated; and G. means in each output channel for accumulating the electrical quantities produced therein, the output signal from each accumulating means being proportional to the total accumulated electrical quantities in that particular output channel and hence also proportional to the total volume of particles falling within a particular particle-size range.
Claim 8
Dependent Claim
19 words
The apparatus according to claim 5 wherein said means for tracking and storing each signal includes a pulse stretcher.
Claim 9
Dependent Claim
50 words
The apparatus according to claim 5 wherein said comparing means includes a plurality of comparators each having first and second inputs, said first input of each comparator being connected to one of the threshold levels and said second input of each of said comparators being connected to the particle-analyzing device.
Claim 10
Dependent Claim
185 words
The apparatus according to claim 7 wherein said logic signal-generating means comprises a trailing edge detector, a leading edge detector, and first and second multivibrators for each comparator except the comparator connected to the lowest threshold level the output of each of the other comparators being connected to an input of both the trailing edge detector and the leading edge detector, the output of said trailing edge detector being connected to said first multivibrator and the output from said leading edge detector being connected to said second multivibrator, an AND circuit connected to said first multivibrator associated with said comparator at the highest threshold level, a plurality of VETO AND circuits each of which is connected to said second multivibrator associated with a comparator connected to one of said threshold levels and to said first multivibrator associated with the comparator connected to the next highest threshold level, and a trailing edge detector and a univibrator connected in series between the comparator connected to the lowest threshold level and one of said VETO AND circuits, said logic signals appearing at the outputs of said AND circuits.
Claim 11
Dependent Claim
45 words
The apparatus according to claim 8 wherein an OR circuit is connected to the output of each of the AND circuits and the other input of each of the OR circuits is connectable to a reference voltage source through a control switch for calibration purposes.
Claim 12
Dependent Claim
21 words
The apparatus according to claim 5 wherein said converting means includes a proportional pump circuit in each of said output channels.
Claim 13
Dependent Claim
21 words
The apparatus according to claim 5 wherein each of said accumulating means in each of said output channels is an integrator.
Claim 14
Dependent Claim
55 words
The apparatus according to claim 5 wherein the output of said univibrator associated with said comparator connected to the lowest threshold is connected to a control trailing edge detector, the output of said control trailing edge detector being connected to said pulse stretcher for resetting same for receiving another electrical signal from the particle-analyzing device.
Claim 15
Dependent Claim
65 words
The apparatus according to claim 12 including a univibrator connected to said control trailing edge detector and a second control trailing edge detector connected to the output of said univibrator, the output of said second trailing edge detector being connected to said multivibrators associated with all the comparators, except the cOmparator connected to the lowest threshold level for resetting the multivibrators for another electric signal.
Claim 16
Dependent Claim
67 words
The apparatus according to claim 5 wherein control circuitry of the particle-analyzing device is connected to all of the AND circuits for controlling the operation thereof and is connected to all of the accumulating means for removing the total accumulated electrical quantities therefrom after a quantity of liquid has been analyzed to prepare the accumulating means for the analysis of another quantity of liquid having particles therein.
Claim 17
Dependent Claim
51 words
The apparatus according to claim 5 wherein the output channels are divided into groups and a pulse stretcher is associated with each group of channels and each pulse stretcher is located in an analog signal channel all of which are connected to a conductor which is connected to the particle-analyzing device.
Claim 18
Dependent Claim
40 words
The apparatus according to claim 15 wherein each analog signal channel includes an amplifier connected between said conductor and said pulse stretcher and a resistor connected between the output of said pulse stretcher and one group of said output channels.
Claim 19
Dependent Claim
223 words
The apparatus according to claim 16 including a group of logic signal channels from said logic signal-generating means associated with each group of output channels, a plurality of AND circuits each connected to one of said logic signal channels and having an output connected to one of said switch means in one of said output channels, a control trailing edge detector connected to the output of the comparator connected to the lowest threshold level and a univibrator connected between the output of said control trailing edge detector and one input of each of said AND circuits and being operable when the amplitude of the electrical signal falls below the threshold of the lowest threshold level to produce a short pulse which is applied to each of said AND circuits to which said logic signal channel is connected for passing a logic signal for a predetermined time period, equal to the duration of the short pulse, to one of said switch means in one of said output channels to allow current to flow through said resistor connected to the output of one of said pulse stretchers and through said one switch means to one of said accumulating means for a predetermined period of time, said converting means comprising each resistor connected between one of said pulse stretchers and a group of said output channels.
Claim 20
Dependent Claim
52 words
The apparatus according to claim 17 wherein a second control trailing edge detector is connected to the output of said univibrator, the output of said second control trailing edge detector being connected to said pulse stretchers for resetting same and to said logic signal-generating means for resetting same for another electrial signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-06 | 1977-11-05 | 1978-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-06 | 1981-11-05 | 1982-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-06 | 1985-11-05 | 1986-05-07 | $7700.00 | Window Closed / Lapsed |