Self-cleaning aperture tube for coulter study apparatus and electrolyte supply system therefor

Claim 2

In a particle measuring apparatus including a vessel for containing a body of particulate liquid suspension to be tested, an aperture tube extending into said vessel and including an aperture, fluid moving means for establishing pressure differentials and adapted for moving the suspension from the vessel through the aperture into and through the aperture tube to a waste collection container, a first electrode in the vessel and a second electrode in the aperture tube to establish an electrical field in the aperture between said vessel and the aperture tube, means including elecrical leads connected to the electrodes and adapted to extend connections to a detector to respond to electrical measuring signals produced across said electrodes with passage of particles through said aperture, the aperture tube having an inlet chamber adapted for fluid connection with a source of particle free liquid, said inlet chamber having said aperture in fluid communication on one side thereof with the suspension in the vessel to permit passage of the suspension through the aperture into the inlet chamber, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, an outlet chamber in fluid connection with said inlet chamber, means for connecting said outlet chamber to said fluid moving means and said waste collection container, means for initially filling the inlet and outlet chambers with particle free liquid; the improvement comprising, the outlet chamber being formed within the inlet chamber, said chambers having a common closed bottom wall, said aperture tube having a restriction in the path of flow of said particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously to wash the zone simultaneously with passage of the suspension through the aperture such that particles which have been measured within the aperture and thereafter passing out of the same immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 3

The invention as claimed in claim 1 in which said restriction is an orifice formed in the wall of the outlet chamber in closely-spaced registry with said aperture.

Claim 4

The invention as claimed in claim 2 in which the aperture is formed in a wafer which is fused to the wall of the inlet chamber and the orifice is formed on a raised dimple on the wall of the outlet chamber.

Claim 5

The invention as claimed in claim 2 in which the aperture and orifice are formed in wafers which are respectively fused to the chamber walls.

Claim 6

The invention as claimed in claim 2 in which the aperture is formed in a wafer which is fused to the wall of the inlet chamber and the orifice is formed on an upstanding jewel which is fused to the wall of the outlet chamber.

Claim 7

In a particle measuring apparatus including a vessel for containing a body of particulate liquid suspension to be tested, an apErture tube extending into said vessel and including an aperture, fluid moving means for establishing pressure differentials and adapted for moving the suspension from the vessel through the aperture into and through the aperture tube to a waste collection container, a first electrode in the vessel and a second electrode in the aperture tube to establish an electrical field in the aperture between said vessel and the aperture tube, means including electrical leads connected to the electrodes and adapted to extend connections to a detector to respond to electrical measuring signals produced across said electrodes with passage of particles through said aperture, the aperture tube having an inlet chamber adapted for fluid connection with a source of particle free liquid, said inlet chamber having said aperture in fluid communication on one side thereof with the suspension in the vessel to permit passage of the suspension through the aperture into the inlet chamber, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, an outlet chamber in fluid connection with said inlet chamber, means for connecting said outlet chamber to said fluid moving means and said waste collection container, means for initially filling the inlet and outlet chambers with particle free liquid; the improvement comprising, the inlet chamber including a first tube and a connecting tube formed normal to the first tube, said outlet chamber being in fluid connection with the connecting tube, said aperture being formed in the connection tube, said aperture tube hairing an orifice formed in the wall of the first tube opening into the connection tube, said orifice being in the path of flow of said particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously to wash and zone simultaneously with passage of the suspension through the aperture such that particles which have been measured within the aperture and thereafter passing out of the same immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 8

In a particle measuring apparatus including a vessel for containing a body of particulate liquid suspension to be tested, an apErture tube extending into said vessel and including an aperture, fluid moving means for establishing pressure differentials and adapted for moving the suspension from the vessel through the aperture into and through the aperture tube to a waste collection container, a first electrode in the vessel and a second electrode in the aperture tube to establish an electrical field in the aperture between said vessel and the aperture tube, means including electrical leads connected to the electrodes and adapted to extend connections to a detector to respond to electrical measuring signals produced across said electrodes with passage of particles through said aperture, the aperture tube having an inlet chamber adapted for fluid connection with a source of particle free liquid, said inlet chamber having said aperture in fluid communication on one side thereof with the suspension in the vessel to permit passage of the suspension through the aperture into the inlet chamber, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, an outlet chamber in fluid connection with said inlet chamber, means for connecting said outlet chamber to said fluid moving means and said waste collection container, means for initially filling the inlet and outlet chambers with particle free liquid; the improvement comprising, the inlet chamber including a first tube and a connecting tube formed normal to the first tube, said outlet chamber being in fluid connection with the connecting tube, said aperture being formed in the connection tube, said aperture tube hairing an orifice formed in the wall of the first tube opening into the connection tube, said orifice being in the path of flow of said particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously to wash and zone simultaneously with passage of the suspension through the aperture such that particles which have been measured within the aperture and thereafter passing out of the same immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 9

In a particle measuring apparatus including a vessel for containing a body of particulate liquid suspension to be tested, an aperture tube extending into said vessel and including an aperture, fluid moving means for establishing pressure differentials and adapted for moving the suspension from the vessel through the aperture into and through the aperture tube to a waste collection container, a first electrode in the vessel and a second electrode in the aperture tube to establish an electrical field in the aperture between said vessel and the aperture tube, means including electrical leads connected to the electrodes and adapted to extend connections to a detector to respond to electrical measuring signals produced across said electrodes with passage of particles through said aperture, the aperture tube having an inlet chamber adapted for fluid connection with a source of particle free liquid, said inlet chamber having said aperture in fluid communication on one side thereof with the suspension in the vessel to permit passage of the suspension through the aperture into the inlet chamber, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, an outlet chamber in fluid connection with said inlet chamber, means for connecting said outlet chamber to said fluid moving means and said waste collection container, means for initially filling the inlet and outlet chambers with particle free liquid; the improvement comprising, the aperture tube being of generally U-shaped configuration with one leg forming the inlet chamber and the other leg forming the outlet chamber, said aperture tube having a restriction in the path of flow of said particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone aNd continuously to wash the zone simultaneously with passage of the suspension through the aperture such that particles which have been measured within the aperture and thereafter passing out of the same immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber. 8. The invention as claimed in claim 7 in which said restriction is a generally V-shaped deformation in the wall of the tube extending therewithin opposite the aperture.

Claim 10

In a particle measuring apparatus including a vessel for containing a body of particulate liquid suspension to be tested, an aperture tube extending into said vessel and including an aperture, fluid moving means for establishing pressure differentials and adapted for moving the suspension from the vessel through the aperture into and through the aperture tube to a waste collection container, a first electrode in the vessel and a second electrode in the aperture tube to establish an electrical field in the aperture between said vessel and the aperture tube, means including electrical leads connected to the electrodes and adapted to extend connections to a detector to respond to electrical measuring signals produced across said electrodes with passage of particles through said aperture, the aperture tube having an inlet chamber adapted for fluid connection with a source of particle free liquid, said inlet chamber having said aperture in fluid communication on one side thereof with the suspension in the vessel to permit passage of the suspension through the aperture into the inlet chamber, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, an outlet chamber in fluid connection with said inlet chamber, means for connecting said outlet chamber to said fluid moving means and said waste collection container, means for initially filling the inlet and outlet chambers with particle free liquid; the improvement comprising, the outlet chamber being a capillary tube formed within the inlet chamber, the inlet chamber having a closed bottom, the outlet chamber terminating at the closed bottom of the inlet chamber at an open end positioned below the aperture, said aperture tube having a restriction in the path of flow of said particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously to wash the zone simultaneously with passage of the suspension through the aperture such that particles which have been measured within the aperture and thereafter passing out of the same immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 11

In a particle measuring apparatus including a vessel for containing a body of particulate liquid suspension to be tested, an aperture tube extending into said vessel and including an aperture, fluid moving means for establishing pressure differentials and adapted for moving the suspension from the vessel through the aperture into and through the aperture tube to a waste collection container, a first electrode in the vessel and a second electrode in the aperture tube to establish an electrical field in the aperture between said vessel and the aperture tube, means including electrical leads connected to the electrodes and adapted to extend connections to a detector to respond to electrical measuring signals produced across said electrodes with passage of particles through said aperture, the aperture tube having an inlet chamber adapted for fluid connection with a source of particle free liquid, said inlet chamber having said aperture in fluid communication on one side thereof with the suspension in the vessel to permit passage of the suspension through the aperture into the inlet chamber, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, an outlet chamber in fluid connection with said inlet chamber, means for connecting said outlet chamber to said fluid moving means and said waste collection container, means for initially filling the inlet and outlet chambers with particle free liquid; the improvement comprising, the outlet chamber being a capillary tube formed within the inlet chamber, the inlet chamber having a closed bottom, the outlet chamber terminating at the closed bottom of the inlet chamber at an open end positioned below the aperture, said aperture tube having a restriction in the path of flow of said particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously to wash the zone simultaneously with passage of the suspension through the aperture such that particles which have been measured within the aperture and thereafter passing out of the same immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 12

The invention as claimed in claim 9 in which said restriction is a generally V-shaped deformation in the wall of the inlet chamber opposite the aperture.

Claim 13

In a particle measuring apparatus including a vessel for containing a body of particulate liquid suspension to be tested, an aperture tube extending into said vessel and including an aperture, fluid moving means for establishing pressure differentials and adapted for moving the suspension from the vessel through the aperture into and through the aperture tube to a waste collection container, a first electrode in the vessel and a second electrode in the aperture tube to establish an electrical field in the aperture between said vessel and the aperture tube, means including electrical leads connected to the electrodes and adapted to extend connections to a detector to respond to electrical measuring signals produced across said electrodes with passage of particles through said aperture, the aperture tube having an inlet chamber adapted for fluid connection with a source of particle free liquid, said inlet chamber having said aperture in fluid communication on one side thereof with the suspension in the vessel to permit passage of the suspension through the aperture into the inlet chambEr, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, an outlet chamber in fluid connection with said inlet chamber, means for connecting said outlet chamber to said fluid moving means and said waste collection container, means for initially filling the inlet and outlet chambers with particle free liquid; the improvement comprising, the outlet chamber being formed within the inlet chamber, the inlet chamber having a closed bottom, the outlet chamber terminating at the closed bottom of the inlet chamber at an open end positioned below the aperture, said aperture tube having a restriction in the path of flow of said particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously to wash the zone simultaneously with passage of the suspension through the aperture such that particles which have been measured within the aperture and thereafter passing out of the same immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 14

In a particle measuring apparatus including a vessel for containing a body of particulate liquid suspension to be tested, an aperture tube extending into said vessel and including an aperture, fluid moving means for establishing pressure differentials and adapted for moving the suspension from the vessel through the aperture into and through the aperture tube to a waste collection container, a first electrode in the vessel and a second electrode in the aperture tube to establish an electrical field in the aperture between said vessel and the aperture tube, means including electrical leads connected to the electrodes and adapted to extend connections to a detector to respond to electrical measuring signals produced across said electrodes with passage of particles through said aperture, the aperture tube having an inlet chamber adapted for fluid connection with a source of particle free liquid, said inlet chamber having said aperture in fluid communication on one side thereof with the suspension in the vessel to permit passage of the suspension through the aperture into the inlet chambEr, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, an outlet chamber in fluid connection with said inlet chamber, means for connecting said outlet chamber to said fluid moving means and said waste collection container, means for initially filling the inlet and outlet chambers with particle free liquid; the improvement comprising, the outlet chamber being formed within the inlet chamber, the inlet chamber having a closed bottom, the outlet chamber terminating at the closed bottom of the inlet chamber at an open end positioned below the aperture, said aperture tube having a restriction in the path of flow of said particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously to wash the zone simultaneously with passage of the suspension through the aperture such that particles which have been measured within the aperture and thereafter passing out of the same immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 15

The invention as claimed in claim 11 in which said restriction is a protrusion in the wall of the outlet chamber opposite the aperture.

Claim 16

The invention as claimed in claim 12 in which longitudinal portions of the walls of the chambers are disposed in abutting relationship and the wall of the outlet chamber opposite the abutting wall is deformed in the shape of a longitudinal channel to provide said inlet chamber.

Claim 17

An aperture tube for use in particle measuring apparatus including a container of particulate liquid suspension into which the aperture tube extends, said tube comprising, an inlet chamber, an outlet chamber in fluid connection with the inlet chamber, said outlet chamber being formed within the inlet chamber, the chambers having a common closed bottom wall, the inlet chamber having an aperture adapted to be in communication on one side thereof with the liquid suspension, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, means for connecting the inlet chamber to a source of particle free liquid, means for connecting the outlet chamber to fluid moving means to move the suspension from the container through the aperture into the spurious signal producing zone, the tube having a restriction in the path of flow of the particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously wash the zone simultaneously with passage of the suspension through the aperture such that particles which have passed through the aperture immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 18

An aperture tube for use in particle measuring apparatus including a container of particulate liquid suspension into which the aperture tube extends, said tube comprising, an inlet chamber, an outlet chamber in fluid connection with the inlet chamber, said outlet chamber being formed within the inlet chamber, the chambers having a common closed bottom wall, the inlet chamber having an aperture adapted to be in communication on one side thereof with the liquid suspension, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, means for connecting the inlet chamber to a source of particle free liquid, means for connecting the outlet chamber to fluid moving means to move the suspension from the container through the aperture into the spurious signal producing zone, the tube having a restriction in the path of flow of the particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously wash the zone simultaneously with passage of the suspension through the aperture such that particles which have passed through the aperture immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 19

The invention as claimed in claim 14 in which said restriction is an orifice formed in the wall of the outlet chamber in closely-spaced registry with said aperture.

Claim 20

The invention as claimed in claim 15 in which the aperture is formed in a wafer which is fused to the wall of the inlet chamber and the orifice is formed on a raised dimple on the wall of the outlet chamber.

Claim 21

The invention as claimed in claim 15 in which the aperture and orifice are formed in wafers which are respectively fused to the chamber walls.

Claim 22

The invention as claimed in claim 15 in which the aperture is formed in a wafer which is fused to the wall of the inlet chamber and the orifice is formed on an upstanding jewel which is fused to the wall of the outlet chamber.

Claim 23

An aperture tube for use in particle measuring apparatus including a container or particulate liquid suspension into which the aperture tube extends, said tube comprising, an inlet chamber, an outlet chamber in fluid connection with the inlet chamber, the inlet chamber having an aperture adapted to be in communcation on one side thereof with the liquid suspension, there bEing a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, means for connecting the inlet chamber to a source of particle free liquid, means for connecting the outlet chamber to fluid moving means to move the suspension from the container through the aperture into the spurious signal producing zone, the tube having a restriction in the path of flow of the particle free liquid, the inlet chamber including a first tube and a connecting tube formed normal to the first tube, said outlet chamber being in fluid connection with the connecting tube, said aperture being formed in the connection tube, and said restriction is an orifice formed in the wall of the first tube opening into the connection tube, whereby the flow velocity of the particle free liquid increases in the spurious signal producing zone and continuously washes the zone simultaneously with passage of the suspension through the aperture such that particles which have passed through the aperture immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 24

An aperture tube for use in particle measuring apparatus including a container or particulate liquid suspension into which the aperture tube extends, said tube comprising, an inlet chamber, an outlet chamber in fluid connection with the inlet chamber, the inlet chamber having an aperture adapted to be in communcation on one side thereof with the liquid suspension, there bEing a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, means for connecting the inlet chamber to a source of particle free liquid, means for connecting the outlet chamber to fluid moving means to move the suspension from the container through the aperture into the spurious signal producing zone, the tube having a restriction in the path of flow of the particle free liquid, the inlet chamber including a first tube and a connecting tube formed normal to the first tube, said outlet chamber being in fluid connection with the connecting tube, said aperture being formed in the connection tube, and said restriction is an orifice formed in the wall of the first tube opening into the connection tube, whereby the flow velocity of the particle free liquid increases in the spurious signal producing zone and continuously washes the zone simultaneously with passage of the suspension through the aperture such that particles which have passed through the aperture immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 25

An aperture tube for use in particle measuring apparatus including a container of particulate liquid suspension into which the aperture tube extends, said tube comprising, an inlet chamber, an outlet chamber in fluid connection with the inlet chamber, the tube being of generally U-shaped configuration with one leg forming the inlet chamber and the other leg forming the outlet chamber, the inlet chamber having an aperture adapted to be in communication on one side thereof with the liquid suspension, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, means for connecting the inlet chamber to a source of particle free liquid, means for connecting the outlet chamber to fluid moving means to move the suspension from the container through the aperture into the spurious signal producing zone, the tube having a restriction in the path of flow of the particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously wash the zone simultaneously with passage of the suspension through the aperture such that particles which have passed through the aperture immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 26

An aperture tube for use in particle measuring apparatus including a container of particulate liquid suspension into which the aperture tube extends, said tube comprising, an inlet chamber, an outlet chamber in fluid connection with the inlet chamber, the tube being of generally U-shaped configuration with one leg forming the inlet chamber and the other leg forming the outlet chamber, the inlet chamber having an aperture adapted to be in communication on one side thereof with the liquid suspension, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, means for connecting the inlet chamber to a source of particle free liquid, means for connecting the outlet chamber to fluid moving means to move the suspension from the container through the aperture into the spurious signal producing zone, the tube having a restriction in the path of flow of the particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously wash the zone simultaneously with passage of the suspension through the aperture such that particles which have passed through the aperture immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 27

The invention as claimed in claim 19 in which said restriction is a generally V-shaped deformation in the wall of the tube extending therewithin opposite the aperture.

Claim 28

An aperture tube for use in particle measuring apparatus including a container of particulate liquid suspension into which the aperture tube extends, said tube comprising, an inlet chamber, a capillary tube outlet chamber formed within the inlet chamber and in fluid connection therewith, the inlet chamber having a closed bottom and an aperture adapted to be in communication on one side thereof with the liquid suspension, the outlet chamber terminating at the closed bottom of the inlet chamber at an open end positioned below the aperture, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, means for connecting the inlet chamber to a source of particle free liquid, means for connecting the outlet chamber to fluid moving means to move the suspension from the container through the aperture into the spurious signal producing zone, the tube having a restriction in the path of flow of the particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously wash the zone simultaneously with passage of the suspension through the aperture such that particles which have passed through the aperture immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamBer.

Claim 29

An aperture tube for use in particle measuring apparatus including a container of particulate liquid suspension into which the aperture tube extends, said tube comprising, an inlet chamber, a capillary tube outlet chamber formed within the inlet chamber and in fluid connection therewith, the inlet chamber having a closed bottom and an aperture adapted to be in communication on one side thereof with the liquid suspension, the outlet chamber terminating at the closed bottom of the inlet chamber at an open end positioned below the aperture, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, means for connecting the inlet chamber to a source of particle free liquid, means for connecting the outlet chamber to fluid moving means to move the suspension from the container through the aperture into the spurious signal producing zone, the tube having a restriction in the path of flow of the particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously wash the zone simultaneously with passage of the suspension through the aperture such that particles which have passed through the aperture immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamBer.

Claim 30

The invention as claimed in claim 22 in which said restriction is a generally V-shaped deformation in the wall of the inlet chamber opposite the aperture.

Claim 31

An aperture tube for use in particle measuring apparatus including a container of particulate liquid suspension into which the aperture tube extends, said tube comprising, an inlet chamber, an outlet chamber formed within the inlet chamber and in fluid connection therewith, the inlet chamber having a closed bottom and an aperture adapted to be in communication on one side thereof with the liquid suspension, the outlet chamber terminating at the closed bottom of the inlet chamber at an open end positioned below the aperture, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, means for connecting the inlet chamber to a source of particle free liquid, means for connecting the outlet chamber to fluid moving means to move the suspension from the container through the aperture into the spurious signal producing zone, the tube having a restriction in the path of flow of the particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously wash the zone simultaneously with passage of the suspension through the aperture such that particles which have passed through the aperture immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 32

An aperture tube for use in particle measuring apparatus including a container of particulate liquid suspension into which the aperture tube extends, said tube comprising, an inlet chamber, an outlet chamber formed within the inlet chamber and in fluid connection therewith, the inlet chamber having a closed bottom and an aperture adapted to be in communication on one side thereof with the liquid suspension, the outlet chamber terminating at the closed bottom of the inlet chamber at an open end positioned below the aperture, there being a zone in the aperture tube proximate to and downstream of the aperture in which spurious signals may normally be produced, means for connecting the inlet chamber to a source of particle free liquid, means for connecting the outlet chamber to fluid moving means to move the suspension from the container through the aperture into the spurious signal producing zone, the tube having a restriction in the path of flow of the particle free liquid to cause the flow velocity thereof to increase in the spurious signal producing zone and continuously wash the zone simultaneously with passage of the suspension through the aperture such that particles which have passed through the aperture immediately are swept out of the spurious signal producing zone by the particle free liquid and moved into the outlet chamber.

Claim 33

The invention as claimed in claim 24 in which said restriction is a protrusion in the wall of the outlet chamber opposite the aperture.

Claim 34

The invention as claimed in claim 25 in which longitudinal portions of the walls of the chambers are disposed in abutting relationship and the wall of the outlet chamber opposite the abutting wall is deformed in the shape of a longitudinal channel to provide said inlet chamber.

Claim 35

An electrolyte supply system for particle measuring apparatus in which an aperture tube is suspended in a vessel for containing a body of particulate liquid suspension to be tested, the tube having an aperture to permit passage of the suspension from the container into the tube, the apparatus including a first electrode in the vessel and a second electrode in the aperture tube to establish an electrical field in the aperture between the vessel and the aperture tube, and means including electrical leads connected to the electrodes and adapted to extend connections to a detector to respond to electrical measuring signals produced across the electrodes with passage of particles through said aperture, said system comprising, the aperture tube having an inlet chamber for introduction of particle free electrolyte, an outlet chamber in fluid connection with the inlet chamber, the aperture tube being mounted at the end opposite the suspended end in a coupling block, an electrolyte reservoir in fluid communication with the inlet chamber, a waste container in fluid communication with the outlet chamber, and fluid moving means connected to the waste container, whereby the fluid moving means will cause electrolyte to pass from the reservoir through the inlet and outlet chambers and into the container and simultaneously will draw suspension through the aperture.

Claim 36

An electrolyte supply system for particle measuring apparatus in which an aperture tube is suspended in a vessel for containing a body of particulate liquid suspension to be tested, the tube having an aperture to permit passage of the suspension from the container into the tube, the apparatus including a first electrode in the vessel and a second electrode in the aperture tube to establish an electrical field in the aperture between the vessel and the aperture tube, and means including electrical leads connected to the electrodes and adapted to extend connections to a detector to respond to electrical measuring signals produced across the electrodes with passage of particles through said aperture, said system comprising, the aperture tube having an inlet chamber for introduction of particle free electrolyte, an outlet chamber in fluid connection with the inlet chamber, the aperture tube being mounted at the end opposite the suspended end in a coupling block, an electrolyte reservoir in fluid communication with the inlet chamber, a waste container in fluid communication with the outlet chamber, and fluid moving means connected to the waste container, whereby the fluid moving means will cause electrolyte to pass from the reservoir through the inlet and outlet chambers and into the container and simultaneously will draw suspension through the aperture.

Claim 37

A system as claimed in claim 27 in which the second electrode is the signal electrode for the particle measuring apparatus, the system including an electrolyte drip chamber and supply conduit interposed between the reservoir and inlet chamber, the drip chamber and conduit being shielded with an electrical insulating member.

Claim 38

A system as claimed in claim 27 in which the coupling block is separable into two portions to permit removal of the aperture tube.

Claim 39

A system as claimed in claim 27 in which the outlet chamber is connected to the top of the waste container and the waste container is a waste drip chamber having a drain conduit provided at the bottom thereof terminating beloW the surface of the waste electrolyte drawn into the waste drip chamber such that the electrical connection between the electrolyte path through the drain conduit and the outlet chamber will be broken by reason of droplet formation of the electrolyte as it enters the waste drip chamber.

Claim 40

The system as claimed in claim 27 in which the volume of electrolyte in the reservoir is maintained constant by continuous supply from an electrolyte source.

Claim 41

The system as claimed in claim 27 in which the fluid moving means comprise a source of vacuum.