Method and apparatus for correcting total particle volume error due to particle coincidence

Claim 3

The method of claim 1 wherein the step of developing said error correction signal includes the step of developing a repetition rate signal which varies in amplitude in accordance with the repetition rate of particle signals and coupling said repetition rate signal to said accumulating means for a predetermined period in response to each particle pulse.

Claim 4

The method of claim 2 in which said predetermined period is a function of particle size.

Claim 5

The method of claim 1 wherein said step of developing an error correction signal includes: A. developing a first signal in response to each particle pulse having a duration related to the particle pulse amplitude, B. converting said repitition rate signal into a second electrical quantity which is capable of being accumulated, said quantity varying in amplitude in accordance with said repetition rate signal and having a duration substantially equal to said first signal duration, and C. accumulating said second electrical quantities with said electrical quantities for varying said output signal.

Claim 6

The method of claim 4 wherein the step of developing said first signal includes the step of: A. measuring the maximum amplitude of each particle pulse, B. developing said first signal in response to passage of each pulse, C. integrating each said first signal to develop an integration signal, D. terminating said first signal when said integration signal exceeds said maximum amplitude of said particle pulse.

Claim 7

In an apparatus for providing output signal data representing the total volume of particulate matter in a quantity of liquid wherein a portion of the liquid is caused to flow through a sensing zone and each particle sensed generates a particle signal having an amplitude proportional to the size of the particle, which particle signal is utilized for producing the output signal data, and wherein said output signal data is accumulated in an accumulation means and is subject to error due to coincidence of particles in the sensing zone, the improvement comprising, error correction means operative to vary in a predetermined manner the output signal data to correct said data for total volume error due to coincidence of particles, said error correction means including rate detection means operative to develop a repetition rate signal varying in amplitude in accordance with the repetition rate of said particles, said output signal data varying in accordance with said repetition rate signal.

Claim 8

In an apparatus for providing output signal data representing the total volume of particulate matter in a quantity of liquid wherein a portion of the liquid is caused to flow through a sensing zone and each particle sensed generates a particle signal having an amplitude proportional to the size of the particle, which particle signal is utilized for producing the output signal data, and wherein said output signal data is accumulated in an accumulation means and is subject to error due to coincidence of particles in the sensing zone, the improvement comprising, error correction means operative to vary in a predetermined manner the output signal data to correct said data for total volume error due to coincidence of particles, said error correction means including rate detection means operative to develop a repetition rate signal varying in amplitude in accordance with the repetition rate of said particles, said output signal data varying in accordance with said repetition rate signal.

Claim 9

The apparatus of claim 6 wherein said error correction means is operative to develop a correction signal varying in amplitude in accordance with the size and repetition rate of said particle signals, said accumulation means being coupled to said error correction means and responsive to said correction signal to vary said output signal data to correct for total volume error due to coincidence of particles.

Claim 10

The apparatus of claim 7 wherein said accumulation means sums said output signal data and said error correction signal.

Claim 11

The apparatus of claim 6 wherein said control means coupled to said rate detection means and operative in response to said particle pulses and said repetition rate signal to develop a correction signal, said accumulation means being coupled to said control means and responsive to said repetition rate signal to vary said output signal data to correct for total volume error.

Claim 12

The apparatus of claim 9 wherein said control means includes, pulse amplitude means responsive to each particle signal to generate a duration signal having a duration related to said particle signal amplitude, said control means operative in response to said duration signal to develop said correction signal having an amplitude related to the amplitude of said repetition rate signal and a duration of said duration signal.

Claim 13

The apparatus of claim 10 wherein said pulse amplitude means includes maximum amplitude determining means coupled to said sensing zone and operative to develop a maximum amplitude signal related to the maximum amplitude of each particle signal, timing means coupled to said maximum amplitude determining means and operative in response to passage of each particle pulse to develop said duration signal having a duration which varies in accordance with the maximum amplitude of said maximum amplitude signal.

Claim 14

The apparatus of claim 11 wherein said maximum amplitude determining means is a pulse stretcher.

Claim 15

The apparatus of claim 11 wherein said timing means includes circuit means coupled to said maximum amplitude determining means and operative in response to passage of each particle pulse to develop said duration signal, integration means coupled to said circuit means and operative to integrate said duration signal and develop an integration signal, comparison means coupled to said integration means, and maximum amplitude determining means and operative in response to said integration signal exceeding said maximum amplitude signal to develop a termination signal for resetting said circuit means integration means and maximum amplitude determining means whereby said duration signal is terminated.

Claim 16

The apparatus of claim 13 wherein said control means include switch means coupled to said rate detection means and said timing means and operative in response to said repetition rate signal amplitude to develop said correction signal having an amplitude related to the amplitude of said repetition rate signal and a duration of said duration signal.

Claim 17

The apparatus of claim 13 wherein said circuit means include a trailing edge detector operative in response to the trailing edge of each particle pulse to develop a trailing edge signal, and a bistable multivibrator coupled to said trailing edge detector and operative in response to said trailing edge signal to develop said duration signal.

Claim 18

Apparatus for producing output signal data representing the total volume of particulate matter in a quantity of liquid containing said particulate matter, utilizing the output signals from a particle analyzing device wherein the quantity of liquid containing said particulate matter is caused to flow through a sensing zone including an electric current path of small dimensions wherein each particle sensed generates a particle signal having an amplitude proportional to the size of the particle sensed, said apparatus comprising: A. means for converting each signal as it occurs into an electrical quantity directly proportional to the amplitude of said signal without regard to its duration and capable of being accumulated, B. means for accumulating said quantities, C. means responsive to the total accumulated quantity providing an output signal proportional to said total quantity, D. means for controlling the operation of said accumulation means, and E. error correction means operative in a predetermined manner to vary the output signal to correct said output signal for its total volume error due to coincidence of particles, said error correction means including rate detection means coupled to said means for converting each signal as it occurs into an electrical quantity and being operative to develop a repetition rate signal which varies in amplitude in accordance with the repetition rate of particle signals, said output signal varying in accordance with said repetition rate signal amplitude.

Claim 19

Apparatus for producing output signal data representing the total volume of particulate matter in a quantity of liquid containing said particulate matter, utilizing the output signals from a particle analyzing device wherein the quantity of liquid containing said particulate matter is caused to flow through a sensing zone including an electric current path of small dimensions wherein each particle sensed generates a particle signal having an amplitude proportional to the size of the particle sensed, said apparatus comprising: A. means for converting each signal as it occurs into an electrical quantity directly proportional to the amplitude of said signal without regard to its duration and capable of being accumulated, B. means for accumulating said quantities, C. means responsive to the total accumulated quantity providing an output signal proportional to said total quantity, D. means for controlling the operation of said accumulation means, and E. error correction means operative in a predetermined manner to vary the output signal to correct said output signal for its total volume error due to coincidence of particles, said error correction means including rate detection means coupled to said means for converting each signal as it occurs into an electrical quantity and being operative to develop a repetition rate signal which varies in amplitude in accordance with the repetition rate of particle signals, said output signal varying in accordance with said repetition rate signal amplitude.

Claim 20

The apparatus of claim 16 wherein said error correction means include control means coupled to said rate detection means and operative in response to said particle pulses and said repetition rate signals to develop error correction signals, said means for accumulating said quantities being coupled to said control means and responsive to said correction signal to vary said output signal data to correct for total volume error.

Claim 21

The apparatus of claim 16 wherein said control means includes, pulse amplitude means responsive to each particle signal to generate a duration signal having a duration related to said particle signal amplitude, said control means operative in response to said duration signal to develop said correction signal having an amplitude related to the amplitude of said reptitition rate signal and a duration of said duration signal.

Claim 22

The apparatus of claim 16 wherein said quantity of liquid containing said particulate matter is a quantity of liquid containing a predetermined number of particles to be sensed.

Claim 23

The apparatus of claim 16 wherein said quantity of liquid containing said particulate matter is a predetermined volume of liquid.