Particle analyzer of the Coulter type including coincidence error correction circuitry

Claim 2

In a particle analyzer subject to coincidence errors in counting particle pulses the combination including: at least first and second sensing means each having substantially the same dimensions and each generating a train of particle pulses in response to passage through each of said sensing means of a sample containing a plurality of particles to be counted, summing circuit means coupled to each of said sensing means for summing together each of said generated trains of particle pulses to develop a summed train of pulses, and circuit means coupled to said summing means and to each of said sensing means for receiving separately said each generated train of particle pulses and said summed train of particle pulses, said circuit means being operative to mathematically change at least the number of particle pulses in said summed train of pulses in accordance with a particular mathematical formula, and to accumulate said numbers of pulses in said generated trains of pulses received and said mathematically changed summed train of pulses to produce an error corrected particle pulse count.

Claim 3

The particle analyzer of claim 1 wherein said circuit means include; counter means coupled to said summing circuit means and to each of said sensing means to accumulate said numbers of pulses, said counter means counting in a first counting direction in response to certain ones of said pulse trains and in the other counting direction in response to other ones of said pulse trains.

Claim 4

The particle analyzer of claim 2 wherein said counter means is an up-down counter.

Claim 5

The particle analyzer of claim 3 wherein said up-down counter counts up in response to each pulse in said generated train of particle pulses from said first and second sensing means and down in response to each pulse in said mathematically changed summed train of pulses.

Claim 6

The particle analyzer of claim 4 wherein said circuit means include divider means coupled between said summing circuit means and said up-down counter and operative in response to said summed train of pulses to develop said mathematically changed number of pulses having one-half the number of pulses as said summed train of pulses.

Claim 7

The particle analyzer of claim 2 wherein said circuit means further include a plurality of detector means, each coupling one of said summing circuit means and said sensing means to said counter means, said detector means each being operative in response to pulses in excess of a predetermined amplitude to develop pulses to be counted.

Claim 8

The particle analyzer of claim 6 wherein said detector means coupled between said sensing means and said counter means further include divider means operative in response to said summed train of detected pulses to develop said mathematically changed number of pulses having one-half the number of pulses as the detected summed train of pulses.

Claim 9

The particle analyzer of claim 1 wherein said first sensing means generates a train of pulses having a first particular number N 1 , said second sensing means generates a train of pulses having a second particular number of N 2 , and said summing means develops a summed train of pulses having a particular number N FD , said circuit means being operative to accumulate said number of pulses in said trains of pulses in accordance with the formula N.sub.O = N.sub.1 + N.sub.2 - (N.sub.FD /2) where N 0 is the error corrected count.

Claim 10

The particle analyzer of claim 1 including a third sensing means having substantially the same dimensions as said first and second sensing means and generatiang a train of particle pulses in response to passage therethrough of a sample containing a plurality of particles to be counted, said summing means being coupled to the said third sensing means for summing said train of particle pulses generated by said third sensing means with said train of pulses developed by said first and second sensing means.

Claim 11

The particle analyzer of claim 9 wherein said first sensing means generates a train of pulses having a first particular number N 1 , said second sensing means generates a train of pulses having a second particular number N 2 , said third sensing means generates a train of pulses having a third particular number N 3 , and said summing means develops a summed train of pulses having a particular number N FD , said circuit means being operative to accumulate said numbers of pulses in said trains of pulses in accordance with the formula ##EQU2## where N 0 is the error corrected count.

Claim 12

The particle analyzer of claim 9 wherein said circuit means include counter means coupled to said summing circuit means and to each of said sensing means to accumulate said numbers of pulses, said counter means counting in a first counting direction in response to certain ones of said pulse trains and the other counting direction in response to other ones of said pulse trains.

Claim 13

The particle analyzer of claim 11 wherein said counter means is an up-down counter.

Claim 14

The particle analyzer of claim 11 wherein said circuit means include three detector means each coupling one of said summing circuit means and said sensing means to said counter means, said detector means each being operative in response to pulses in excess of a predetermined amplitude to develop pulses to be counted.

Claim 15

The particle analyzer of claim 13 wherein said detector means coupling said summing circuit means to said counter means include first divider means operative in response to said trains of pulses coupled thereto to develop trains of pulses having one-half the number of pulses as coupled thereto, and second divider means operative in response to said summed train of detected pulses to develop said mathematically changed number of pulses having one-sixth the number of pulses as said detected summed train of pulses.

Claim 16

The particle analyzer of claim 14 wherein said up-down counter counts up in response to each pulse from said first divider means and down in response to each pulse from said second divider means.

Claim 17

In a particle analyzer subject to coincidence errors in counting particle pulses the combination including: a first sensing means for generating a first train of particle pulses having a first number of particle pulses in response to passage through said first sensing means of a sample containing a plurality of particles to be counted, a second sensing means having substantially the same dimensions as said first sensing means for generatiang a second train of particle pulses having a second number of particle pulses in response to passage through said second sensing means of a sample containing a plurality of particles to be counted, summing circuit means coupled to said first and second sensing means for summing together said first and second trains of particle pulses to develop a third train of particle pulses having a third number of particle pulses, first, second and third pulse detection means coupled to said first and second sensing means and said summing circuit means respectively and operative in response to pulses in excess as a predetermined amplitude to develop first, second and third trains having first, second and third numbers of detected pulses, divider means coupled to said third detection means and operative in response to said third detected pulses to develop a train of pulses having one-half the number of said third detected pulses, and up-down counter means coupled to said first and second detection means and said divider means and operative in response to said pulses in said first and second trains of detected pulses to count up and operative in response to said pulses from said divider means to count down, said counter means developing a total count therein which is an error corrected particle pulse count.

Claim 18

In a particle analyzer subject to coincidence errors in counting particle pulses the combination including: a first sensing means for generating a first train of particle pulses having a first number of particle pulses in response to passage through said first sensing means of a sample containing a plurality of particles to be counted, a second sensing means having substantially the same dimensions as said first sensing means for generatiang a second train of particle pulses having a second number of particle pulses in response to passage through said second sensing means of a sample containing a plurality of particles to be counted, summing circuit means coupled to said first and second sensing means for summing together said first and second trains of particle pulses to develop a third train of particle pulses having a third number of particle pulses, first, second and third pulse detection means coupled to said first and second sensing means and said summing circuit means respectively and operative in response to pulses in excess as a predetermined amplitude to develop first, second and third trains having first, second and third numbers of detected pulses, divider means coupled to said third detection means and operative in response to said third detected pulses to develop a train of pulses having one-half the number of said third detected pulses, and up-down counter means coupled to said first and second detection means and said divider means and operative in response to said pulses in said first and second trains of detected pulses to count up and operative in response to said pulses from said divider means to count down, said counter means developing a total count therein which is an error corrected particle pulse count.