AUTOMATIC COUNTING SYSTEM FOR FLUID SUSPENDED PARTICLE

• US 3,577,162 A
• Filed: 03/21/1969
• Issued: 05/04/1971
• Est. Priority Date: 04/19/1968
• Status: Expired due to Term

• Current Assignee: Gaehwiler Hermann, Kurt Schoen
• Original Assignee: Gaehwiler Hermann, Kurt Schoen
• Inventors: GAEHWILER HERMANN, Schoen, Kurt
• Application Number:
  US04/809,332
• Time in Patent Office: 774 Days
• US Class Current: 250/577
• CPC Class Codes: G01N 15/12 by observing changes in resistance or impedance across apertures when traversed by individual particles, e.g. by using the Coulter principle

Abstract

A novel counting system for counting particles suspended in a fluid medium is disclosed. The counting system comprises electrode means for sensing the presence of particles in a fluid means and producing a signal representative thereof; conveying means for conveying the fluid medium through said electrode means into a measuring tube; an upper and a lower spaced apart fluid level sensing means disposed at the measuring tube; and counter means coupled with said sensing means and said electrode means for counting said signals, said counter means being turned on by said lower sensing means when the fluid reaches the lower level in the measuring tube, and being turned off by said upper sensing means when the fluid reaches the upper level in the measuring tube.

Claims

2. A counting system as defined in claim 1, further including reversing switch means for said conveying means to effect drainage of the fluid medium, said reversing switch means being coupled with said counter means and being actuated when said counter means is turned off.

3. A system for counting particles suspended in a fluid medium, said system comprising:

a light-transmitting measuring tube for receiving the fluid medium, the particles of which are to be counted;

a measuring head supported at one end of said measuring tube, said measuring head embodying electrode support means mounted at said one end of said measuring tube and a measuring path member possessing means for providing at least one predetermined electrical resistance measuring path defining at least one throughflow passageway for the fluid medium from one side to the opposite side thereof;

electrode means supported by said electrode support means for sensing the presence of particles in said fluid means as it moves through said throughflow passageway of said electrical resistance measuring path and for producing electrical signals representative of the presence of said particles, said electrode means comprising a pair of electrodes mounted at said electrode support means for cooperation with opposite sides of said through-flow passageway, conveying means for conveying said fluid medium through said throughflow passageway of said electrical resistance measuring path and past said electrode means into said measuring tube;

a first and a second fluid level sensing means disposed at said measuring tube in spaced relationship from one another;

counter means coupled with said first and second sensing means and said electrode means for counting said electrical signals, said counter means being turned-on by said first sensing means when the fluid medium reaches a fist level in said measuring tube and being turned off by said second sensing means when the fluid medium reaches a second level in said measuring tube;

each said fluid level sensing means comprising a photocell and light source; and

means for mounting each respective photocell and light source at a predetermined angle from one another along the outside of said measuring tube such that light from a given one of said light sources will impinge upon the respective associated photocell substantially only when said measuring tube is devoid of fluid at the level of said respective photocell and light source and therefore being totally reflected at an inner glass-air boundary layer of said measuring tube.

4. The system as defined in claim 3, further including a switching device responsive to signals transmitted by said second fluid level sensing means for reversing the conveying direction of the fluid medium by said conveying means.