1. A turbidity head for a turbidity sensor or probe comprising:
a light source providing an outgoing light ray toward a fluid sample;
a detector capable of detecting an incoming light ray reflected from the fluid sample;
an isolator separating the light source from the detector portion; and
a first reflector in the path of either the outgoing light ray or the incoming light ray;
wherein the first reflector is positioned to reflect either the outgoing light ray or the incoming light ray to achieve a measurement angle defined between the outgoing light ray and the incoming light ray of ninety degrees plus-or-minus two and a half degrees.
2. The turbidity head of claim 1, wherein the first reflector is positioned at a tilt angle between 0\xb0 to 45\xb0.
3. The turbidity head of claim 2 wherein the first reflector is positioned at a tilt angle between about 10\xb0 to about 30\xb0.
4. The turbidity head of claim 1, wherein the first reflector includes a prism, a reflective film, a reflective coating, and combinations thereof.
5. The turbidity head of claim 4, wherein the first reflector is a prism having one reflective side.
6. The turbidity head of claim 5, wherein the first reflector is positioned to reflect the outgoing light ray and a second reflector is positioned to reflect the incoming light ray.
7. The turbidity head of claim 5, wherein the reflective side includes the reflective coating or the reflective film thereon.
8. The turbidity head of claim 1, wherein the first reflector is positioned such that the incident angle is less than the critical angle.
9. The turbidity head of claim 1, wherein the turbidity head has a central longitudinal axis and whichever of the light source or the photo detector is in the path of the first reflector has a central longitudinal axis that is generally parallel to the central longitudinal axis of the turbidity head.
10. The turbidity head of claim 9, wherein the reflector is a parallelepiped prism, the prism being positioned at a tilt angle between 0\xb0 to 45\xb0 that places the second end of the prism closer to the central longitudinal axis of the turbidity head than the first end of the prism.
11. The turbidity head of claim 1, further comprising a housing having a maximum diameter of about 13 mm, the housing enclosing the light source, the photodetector, the isolator, and the first reflector.
12. The turbidity head of claim 11, wherein the housing is a cap having a closed end that includes an optics aperture.
13. The turbidity head of claim 4, wherein the first reflector is a reflective film.
14. The turbidity head of claim 13, wherein the first reflector is positioned to reflect the outgoing light ray and a second reflector is positioned to reflect the incoming light ray.
15. The turbidity head of claim 1, wherein the turbidity head has a central longitudinal axis and whichever of the light source or the photo detector that does not include the reflector has a central longitudinal axis that is oriented at about a 5\xb0 to about a 60\xb0 angle to the central longitudinal axis of the turbidity head.
16. A turbidity sensor comprising:
a watertight housing that houses a light source providing an outgoing light ray toward a fluid sample, a detector capable of detecting an incoming light ray reflected from the fluid sample, an isolator separating the light source from the detector portion, a first reflector in the path of either the outgoing light ray or the incoming light ray, and a circuit board electrically coupled to the light source and the detector;
wherein the first reflector is positioned to reflect either the outgoing light ray or the incoming light ray to achieve a measurement angle defined between the outgoing light ray and the incoming light ray of ninety degrees plus-or-minus two and a half degrees.
17. The turbidity sensor of claim 16, further comprising an electrical connector electrically coupled to the circuit board, the electrical connector being capable of electrically coupling the circuit board to a water monitoring device.
18. The turbidity sensor of claim 17, wherein the electrical connector is a wet mateable connector.
19. The turbidity sensor of claim 16, wherein the water tight housing includes a cap that covers an optics receptacle that receives the light source, the photodetector, and the reflector.
20. The turbidity sensor of claim 16, further comprising a second reflector, wherein the first reflector is positioned to reflect the outgoing light ray and the second reflector is positioned to reflect the incoming light ray.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An exhaust silencer assembly, comprising:
an eductor disposed downstream of an auxiliary power unit and including an entrance opening at a forward axial end thereof, the entrance opening configured to receive exhaust airflow from the auxiliary power unit;
an acoustic-attenuating porous liner disposed within an interior of the eductor axially downstream of the entrance opening, the porous liner separating a radially outer plenum from a radially inner plenum of the eductor;
a discharge pipe extending from the auxiliary power unit and communicating with the exhaust silencer assembly downstream of the entrance opening of the educator, wherein the discharge pipe extends through both an outer casing of the eductor and the porous liner; and
an air inlet duct secured to the eductor and communicating with the outer plenum of the eductor via a cooling air inlet opening therein.
2. The exhaust silencer assembly of claim 1, wherein the eductor receives a by-pass airflow from the discharge pipe, a cooling airflow from the air inlet duct, and exhaust airflow from the auxiliary power unit and includes a plurality of mixing zones where the airflows are mixed therein.
3. The exhaust silencer assembly of claim 1, wherein the eductor includes a by-pass plenum disposed forward of the outer plenum, the by-pass plenum communicates with the discharge pipe and includes an opening to the inner plenum that is disposed downstream of the entrance opening of the eductor.
4. The exhaust silencer assembly of claim 1, wherein the eductor includes a by-pass plenum disposed aft of the outer plenum, the by-pass plenum communicates with the discharge pipe and includes an opening to the inner plenum that is disposed downstream of the entrance opening of the eductor.
5. An assembly, comprising:
an auxiliary power unit;
an eductor disposed downstream of the auxiliary power unit and including an entrance opening at a forward axial end thereof, the entrance opening configured to receive exhaust airflow from the auxiliary power unit, the eductor including a cooling air inlet opening therein and an acoustic-attenuating porous liner disposed within an interior thereof;
a discharge pipe extending from the auxiliary power unit and communicating with the eductor downstream of the entrance opening; and
an air inlet duct secured to the eductor and communicating with the interior thereof via the cooling air inlet opening;
wherein the eductor receives a by-pass airflow from the discharge pipe, a cooling airflow from the air inlet duct, and exhaust airflow from the auxiliary power unit.
6. The assembly of claim 5, further comprising a heat exchanger disposed along the air inlet duct.
7. The assembly of claim 5, wherein the assembly is disposed in the tail section of an aircraft.
8. The assembly of claim 5, wherein the discharge pipe extends through both an outer casing of the eductor and the porous liner.
9. The assembly of claim 6, wherein the eductor includes a by-pass plenum disposed at a forward end thereof, the by-pass plenum communicates with the discharge pipe and includes an opening to the remainder of the eductor that is disposed downstream of the entrance opening.
10. The assembly of claim 5, wherein the eductor includes a by-pass plenum disposed at an aft end thereof, the by-pass plenum communicates with the discharge pipe and includes an opening to the remainder of the eductor that is disposed downstream of the entrance opening.
11. The assembly of claim 5, further comprising a by-pass plenum disposed forward of the eductor, the by-pass plenum communicates with the discharge pipe and includes an opening that is disposed at or downstream of the termination of a turbine flow casing.
12. The assembly of claim 5, further comprising an exhaust duct and wherein the discharge pipe communicates directly with the exhaust duct downstream of the eductor.
13. An exhaust silencer assembly, comprising:
an eductor disposed downstream of an auxiliary power unit and including an entrance opening at a forward axial end thereof, the entrance opening configured to receive exhaust airflow from the auxiliary power unit;
an acoustic-attenuating porous liner disposed within an interior of the eductor axially downstream of the entrance opening, the porous liner separating a radially outer plenum from a radially inner plenum of the eductor;
an exhaust duct downstream of the eductor, the exhaust duct configured to receive airflow from the eductor; and
a discharge pipe extending from the auxiliary power unit and communicating with the exhaust duct downstream of the eductor.
14. The exhaust silencer assembly of claim 13, wherein the exhaust duct receives a by-pass airflow from the discharge pipe and a by-pass mixing zone occurs downstream of the eductor in the exhaust duct.
15. The exhaust silencer assembly of claim 13, wherein the eductor includes an air inlet duct secured to the eductor and communicating with the outer plenum of the eductor via a cooling air inlet opening.
16. The exhaust silencer assembly of claim 1, wherein the eductor includes a by-pass plenum that communicates with the discharge pipe and includes an opening to the remainder of the eductor that is disposed downstream of the entrance opening.
17. An exhaust silencer assembly, comprising:
an eductor disposed downstream of an auxiliary power unit including an entrance opening configured to receive exhaust airflow from the auxiliary power unit;
an acoustic-attenuating porous liner disposed within an interior of the eductor axially downstream of the entrance opening, the porous liner separating a radially outer plenum from a radially inner plenum of the eductor;
a cooling air inlet opening in the eductor;
a discharge pipe extending from the auxiliary power unit and communicating with the eductor downstream of the entrance opening; and
an annular by-pass plenum within the eductor, the by-pass plenum communicates with the discharge pipe.