Particle counter with laser diode
A liquid particle counter for optically detecting an unconstrained particle suspended in a flowing liquid includes a sample chamber having a liquid inlet and a liquid outlet; a laser diode module producing a symmetrically collimated laser beam; a beam shaping optical system directing the laser beam at the sample chamber; and an optical detector located to detect light scattered by the particle in the sample chamber, the detector producing an electric signal characteristic of a parameter of the particle. The laser beam has an energy of a watt or more and passed through an aperture in a black glass aperture element in the sample chamber. The black glass aperture element removes diffracted and stray light from the beam without damage to the sample chamber.
1. A device for optically detecting an unconstrained single particle suspended in a flowing liquid, said device comprising:
a sample chamber having a liquid inlet and a liquid outlet, said sample chamber adapted to permit said single particle to flow essentially without constraint between said inlet and outlet;
a laser diode module producing a symmetrically collimated laser beam having a power of one watt or more;
a beam shaping optical system directing said laser beam at said sample chamber; and
an optical detector located to detect light scattered by said single particle in said sample chamber, said detector producing an electric signal characteristic of a parameter of said single particle.
2. A device as in claim 1 wherein said device is a non-in-situ particle counter.
3. A device as in claim 2 wherein said device is a volumetric particle counter.
4. A device as in claim 1 wherein said device is an in-situ particle counter.
5. A device as in claim 1 wherein said sample chamber includes a glass or crystalline aperture element having an aperture and said beam shaping system directs said laser beam through said aperture.
6. A device as in claim 5 wherein said glass or crystalline aperture element is made of light-absorbing glass or light-absorbing crystalline material.
7. A device as in claim 6 wherein said glass or crystalline aperture element is made of NG1 black glass or black diamond.
8. A device as in claim 5 wherein said device includes a light baffle chamber, and said glass aperture element is located between said light baffle chamber and said sample chamber.
9. A device as in claim 5 wherein said light baffle chamber is fluidly connected to said inlet and outlet to permit said liquid to flow through it.
10. A device as in claim 1 wherein said laser diode module a unique m.o.d.e.™ laser diode module.
11. A device as in claim 1 wherein said beam shaping optics includes an aperture system blocking a third or more of the power of said laser beam.
12. A device for optically detecting an unconstrained single particle suspended in a flowing liquid, said device comprising:
a sample chamber having a liquid inlet and a liquid outlet, said sample chamber adapted to permit said single particle to flow essentially without constraint between said inlet and outlet;
a laser diode module producing a laser beam having a power of one watt or greater;
a beam shaping optical system directing said laser beam at said sample chamber; and
an optical detector located to detect light scattered by said single particle in said sample chamber, said detector producing an electric signal characteristic of a parameter of said single particle.
13. A method of detecting an unconstrained single particle in a flowing liquid, said method comprising:
flowing said liquid containing said unconstrained particle;
providing a laser diode producing a laser beam of one watt or more;
directing said laser beam at said liquid flow;
collecting light scattered by said particle in said liquid; and
providing an output signal characteristic of a parameter of said single particle detected in said flowing liquid.
14. A method as in claim 13 wherein said flowing comprises flowing said liquid through a sample chamber having a glass or crystalline aperture element having an aperture; and said directing comprises directing said laser beam through said aperture.
15. A method as in claim 14 and further comprising cooling said glass or crystalline aperture element with said fluid flow.
16. A device for optically detecting an unconstrained single particle suspended in a flowing fluid, said device comprising:
a fluid inlet for producing a fluid flow essentially without constraining the flow of single particles that may be in said fluid flow;
a laser diode module producing a symmetrically collimated laser beam;
a beam shaping optical system directing said laser beam at said fluid flow, said laser beam having a power of one watt or more; and
an optical detector located to detect light scattered by said particle in said fluid flow, said detector producing an electric signal characteristic of a parameter of said single particle.
17. A method for optically detecting an unconstrained single particle suspended in a fluid, said method comprising:
flowing said fluid containing said unconstrained single particle;
providing a laser diode module producing a symmetrically collimated laser beam having a power of one watt or more;
directing said laser beam at said fluid flow through an aperture of a glass or crystalline aperture element having an aperture;
collecting light scattered by said particle in said fluid; and
providing an output characteristic of a parameter of said single particle detected in said flowing fluid.
18. A method as in claim 17 , wherein said glass or crystalline aperture element is made of light-absorbing glass or light-absorbing crystalline material.
19. A method as in claim 18 , wherein said glass or crystalline aperture element is made of NG1 black glass or black diamond.
20. A device as in claim 1 , wherein said sample chamber is made of plastic.
21. A device as in claim 12 , wherein said sample chamber is made of plastic.