Particle analyzing method and apparatus having pulse amplitude modification for particle volume linearization

Claim 3

The method according to claim 1 in which its recited steps are caused to coact to yield the pulse modified amplitude according to the formula: MA C + (C - SH) in which MA is the modified amplitude, C is the center amplitude, and SH is the average shoulder amplitude.

Claim 4

The method according to claim 1 in which said deriving includes the obtaining of the average amplitude of said shoulder amplitudes.

Claim 5

The method according to claim 3 in which said deriving further includes comparing said shoulder average amplitude with said center amplitude.

Claim 6

The method according to claim 4 in which said deriving includes measuring the difference between said center amplitude and said shoulder average amplitude.

Claim 7

The method according to claim 5 in which said deriving includes defining a first factoring constant that is proportional to the variations in shape of the particle pulses, and applying said first factoring constant to said shoulder average amplitude.

Claim 8

The method according to claim 6 in which said deriving includes defining a second factoring constant that is proportional to the total amount of amplitude modification and applying it to the difference between said center amplitude and said average shoulder amplitude.

Claim 9

The method according to claim 7 in which all of the included aspects of said deriving and said adding yield a modified pulse amplitude according to the formula: MA C - k2 (k1SH - C) in which MA is the modified amplitude, C is the center amplitude, SH is the average shoulder amplitude, and k1 and k2 are factoring constants.

Claim 10

The method according to claim 1 in which said measuring of said shoulder amplitudes is accomplished with pulse delaying techniques which enable said measuring of both shoulder amplitudes at the same time.

Claim 11

The method according to claim 9 in which said measuring of said center amplitude is accomplished with pulse delaying techniques which enable said measuring of said center amplitude and both said shoulder amplitudes at the same time for comparing their relative magnitudes.

Claim 12

The method according to claim 10 including the step of defining said same time to be the time at which the delayed particle-pulse attains its center amplitude.

Claim 13

The method according to claim 10 in which the particle-pulse is twice delayed by separately defined delay values.

Claim 14

The method according to claim 12 in which said delay values are equal, to enable said deriving to develop an average shoulder amplitude coincident in time with said center amplitude.

Claim 15

The method according to claim 12 in which the sum of said delay values is a duration substantially equal to the duration that an ideal particle-pulse will be above its half amplitude.

Claim 16

Apparatus for proportionately modifying the amplitude of particle-pulses of the type having a center portion with 2 shoulder portions on either side and produced by a Coulter type of scanning aperture; whereby the modified amplitude will be the same for all particles of the same volume, regardless of their differing trajectories through the aperture, said apparatus comprising: means for measuring the amplitude of a particle-pulse at its center and at two shoulder points on opposite sides of the center, means for deriving from the relative magnitudes of said three amplitudes an increment of amplitude error, and means for adding said increment of amplitude error to said center amplitude to obtain the desired modified amplitude.

Claim 17

Apparatus for proportionately modifying the amplitude of particle-pulses of the type having a center portion with 2 shoulder portions on either side and produced by a Coulter type of scanning aperture; whereby the modified amplitude will be the same for all particles of the same volume, regardless of their differing trajectories through the aperture, said apparatus comprising: means for measuring the amplitude of a particle-pulse at its center and at two shoulder points on opposite sides of the center, means for deriving from the relative magnitudes of said three amplitudes an increment of amplitude error, and means for adding said increment of amplitude error to said center amplitude to obtain the desired modified amplitude.

Claim 18

The apparatus according to claim 15 in which its recited means are constructed and arranged to coact to yield the pulse modified amplitude according to the formula: MA C + (C -SH) in which MA is the modified amplitude, C is the center amplitude, and SH is the average shoulder amplitude.

Claim 19

The apparatus according to claim 15 in which said means for measuring said shoulder amplitudes includes pulse delaying means which enable measuring of both shoulder amplitudes at the same time.

Claim 20

The apparatus according to claim 17 in which said means for measuring said center amplitude includes pulse delaying means which enable measuring of said center amplitude and both said shoulder amplitudes at the same time for comparing their relative magnitudes.

Claim 21

Apparatus according to claim 18 in which said measuring means includes pulse center finder means for receiving an output from said delaying means and for defining by a trigger signal and same time to be the time at which a delayed particle pulse attains its center amplitude.

Claim 22

Apparatus according to claim 18 in which said pulse delaying means includes means for twice delaying the particle-pulse by separately defined delay values.

Claim 23

The apparatus according to claim 15 in which said deriving means includes means for obtaining the average amplitude of said shoulder amplitudes.

Claim 24

The apparatus according to claim 21 in which said deriving means further includes means for comparing said shoulder average amplitude with said center amplitude.

Claim 25

The apparatus according to claim 22 in which said deriving means includes means for measuring the differences between said center amplitude and said shoulder average amplitude.

Claim 26

The apparatus according to claim 23 in which said deriving means includes means for defining a first factoring constant that is proportional to the variations in shape of the particle pulses, and means for applying said first factoring constant to said shoulder average amplitude.

Claim 27

The apparatus according to claim 24 in which said deriving means includes means for defining a second factoring constant that is proportional to the total amount of amplitude modification and means for applying it to the difference between said center amplitude and said average shoulder amplitude.

Claim 28

Apparatus according to claim 25 in which all of the recited means included in said deriving means and said adding means are interconnected to generate a modified pulse amplitude according to the formula: MA C - k2 (k1SH - C) in which MA is the modified amplitude, C is the center amplitude, SH is the average shoulder amplitude, and k1 and k2 are factoring constants.

Claim 29

Apparatus for proportionately modifying the amplitude of particle-pulses of the type having a center portion with 2 shoulder portions on either side and derived from a Coulter type of scanning aperture, said apparatus comprising: pulse delay means having an input, for receiving particle-pulses from a scanning aperture, and first and second outputs from which are respectively delivered each received pulse delayed by first and second different time values; an amplitude summing means having inputs respectively coupled to said delay means input and to said delay means second output; pulse center finder means coupled to said delay means first output; an amplitude substracting means having inputs respectively coupled to said delay means first output and an output of said summing means; differentiating means having inputs respectively coupled to said delay means first output and an output of said subtracting means; output means having a control input coupled to an output of said pulse center finder means, a signal input coupled to an output of said amplitude differentiating means, and an output from which, at the time of the center amplitude of a first delayed pulse, is obtainable a pulse amplitude modified proportionately to the shape of the associated received particle-pulse.

Claim 30

Apparatus for proportionately modifying the amplitude of particle-pulses of the type having a center portion with 2 shoulder portions on either side and derived from a Coulter type of scanning aperture, said apparatus comprising: pulse delay means having an input, for receiving particle-pulses from a scanning aperture, and first and second outputs from which are respectively delivered each received pulse delayed by first and second different time values; an amplitude summing means having inputs respectively coupled to said delay means input and to said delay means second output; pulse center finder means coupled to said delay means first output; an amplitude substracting means having inputs respectively coupled to said delay means first output and an output of said summing means; differentiating means having inputs respectively coupled to said delay means first output and an output of said subtracting means; output means having a control input coupled to an output of said pulse center finder means, a signal input coupled to an output of said amplitude differentiating means, and an output from which, at the time of the center amplitude of a first delayed pulse, is obtainable a pulse amplitude modified proportionately to the shape of the associated received particle-pulse.

Claim 31

Apparatus according to claim 27 in which all of said means are constructed and arranged to generate a modified amplitude defined by to formula: MA C + (C - SH) in which MA is the modified amplitude, C is the center amplitude, and SH is the average shoulder amplitude.

Claim 32

Apparatus according to claim 27 in which said pulse delay means is constructed to define said first time value to be one-half said second time value.

Claim 33

Apparatus according to claim 27 in which a first gain control means is coupled to said amplitude summing means for defining a first factoring constant that is proportional to variations in shape of the particle-pulses.

Claim 34

Apparatus according to claim 30 in which said summing means is defined by an operational amplifier having coupled to one input a summing junction for receiving the particle-pulse and its second delayed counterpart, and said gain control means is defined by a resistive feedback portion of said operational amplifier.

Claim 35

Apparatus according to claim 30 in which a second gain control means is coupled to the output of said subtracting means for defining a second factoring constant that is proportional to the total amount of amplitude modificaTion.

Claim 36

Apparatus according to claim 32 in which said pulse delay means, said first and second gain control means are adjustable dependent upon the size of the scanning aperture.

Claim 37

Apparatus according to claim 32 in which all of said means are constructed and arranged to generate a modified amplitude defined by the formula: MA C - k2 (k1SH - C) in which MA is the modified amplitude, C is the center amplitude, SH is the average shoulder amplitude, and k1 and k2 are factoring constants.