Optical flow cell

1. An optical flow cell comprising:

a housing forming an enclosed and elongated fluid channel arranged along a first axis;

a first light guide; and

a second light guide generally concentrically arranged along a second axis and on opposite side walls of the fluid channel, said first and second light guides having ends removed in situ to provide a sensing gap,

wherein the housing comprises at least a first part, a second part and a seal located between the first and the second part, and

wherein the first part is configured to form the enclosed and elongated fluid channel arranged along the first axis, the fluid channel having an open side, and the corresponding second part is configured to close the open side of the fluid channel.

2. The optical flow cell according to claim 1 , wherein the first light guide comprises an exit surface, where light is emitted, and wherein the second light guide comprises an entrance surface, where emitted light is received, wherein the exit surface area is smaller than the entrance surface area as a result of a diameter of the first light guide being smaller than a diameter of the second light guide.

3. The optical flow cell according to claim 1 , wherein the seal encloses edges of opposing surfaces of the first and second parts and/or the seal comprises a first and second bore arranged on the second axis, wherein the first bore is arranged to allow the first light guide to protrude through the first bore and the second light guide is arranged to protrude through the second bore.

4. The optical flow cell according to claim 1 , wherein the first light guide is enclosed in a first connector part and the second light guide is enclosed in a second connector part.

5. The optical flow cell according to claim 4 , further comprising:

a first fastener arranged to fasten or secure the first connector part to the housing; and

a second fastener arranged to fasten or secure the second connector part to the housing.

6. A method of producing the optical flow cell according to claim 1 , the method comprising:

inserting opposed first and second light guides into an optical flow cell housing along a second axis such that their ends are abutted, adjacent, or closely spaced;

removing one or both end portions of the continuous lights guide in situ to form a sensing gap of a width (d).

7. The method according to claim 6 , wherein the removing of portions of the light guides is performed by cutting the light guides adjacent to a first side wall of the fluid channel and cutting the continuous light guide adjacent to a second opposing side wall of the fluid channel.

8. The method according to claim 6 , wherein the removing of a portion of the continuous light guide is performed in a motion along the first axis and perpendicular to the second axis.

9. The method according to claim 6 , wherein the removing of a portion of the continuous light guide is performed in a motion perpendicular to the first axis and perpendicular to the second axis.

10. The method according to claim 6 , wherein the removing is performed using a diamond saw or laser ablation.

11. The optical flow cell according to claim 1 , wherein the first light guide and the second light guide are optical light guides.

12. The optical flow cell according to claim 1 , wherein the seal defines a saddle shaped surface, where a length direction of the saddle shaped surface is perpendicular to the first axis.

13. The optical flow cell according to claim 1 , wherein the first housing part and the second housing art are respectively single unitary pieces.

14. An optical flow cell comprising:

a housing forming an enclosed and elongated fluid channel arranged along a first axis;

a first light guide; and

a second light guide generally concentrically arranged along a second axis and on opposite side walls of the fluid channel, said first and second light guides having ends removed in situ to provide a sensing gap,

wherein the housing comprises at least a first part, a second part and a seal located between the first and the second part,

wherein the first part is configured to form the enclosed and elongated fluid channel arranged along the first axis, the fluid channel having an open side, and the corresponding second part is configured to close the open side of the fluid channel, and

wherein the first axis and the second axis intersect each other, such that the first axis and the second axis are perpendicular to each other.

15. A method of producing the optical flow cell according to claim 14 , the method comprising:

inserting opposed first and second light guides into an optical flow cell housing along a second axis such that their ends are abutted, adjacent, or closely spaced;

removing one or both end portions of the continuous lights guide in situ to form a sensing gap of a width (d).