Debris monitoring

1. A debris monitoring system comprising:

a housing;

a receptacle defining an opening, the receptacle being releasably engageable with the housing to receive debris into the receptacle through the opening;

a first emitter supported on the housing on one side of the opening and arranged to emit a signal across at least a portion of the opening; and

a first receiver supported on the housing on an opposite side of the opening and arranged to receive the signal emitted by the first emitter across the opening;

wherein the receptacle is movable with respect to the first emitter and the first receiver.

2. The debris monitoring system of claim 1 wherein the opening is substantially rectangular and the first receiver and the first emitter are substantially opposed to one another across the opening.

3. The debris monitoring system of claim 1 further comprising a second emitter arranged to direct a signal across the opening.

4. The debris monitoring system of claim 3 wherein the first and second emitter are arranged relative to one another such that their respective signals intersect within the opening.

5. The debris monitoring system of claim 1 wherein the first receiver is less than about 0.25 inches from the first emitter.

6. The debris monitoring system of claim 3 wherein the second emitter is supported on the housing and the receptacle is movable relative to the second emitter.

7. The debris monitoring system of claim 1 further comprising a controller supported on the housing, wherein the first emitter and the first receiver are each in wireless communication with the controller.

8. The debris monitoring system of claim 7 wherein the wireless communication comprises infrared communication.

9. A debris monitoring system comprising:

a housing;

a receptacle configured to be carried by the housing and defining an opening to receive debris into the receptacle;

a plurality of first emitters and a plurality of second emitters, each emitter of each plurality of emitters arranged to emit a signal across at least a portion of the opening and positioned on the housing adjacent the receptacle;

a first receiver positioned on an opposite side of the opening from the plurality of first emitters to receive reflections of the signal emitted by each of the plurality of first emitters and the first receiver disposed toward the opening to receive an unreflected portion of the signal emitted by each of the plurality of second emitters across at least a portion of the opening; and

a second receiver positioned on an opposite side of the opening from the plurality of second emitters to receive reflections of the signal emitted by each of the plurality of second emitters and the second receiver disposed toward the opening to receive an unreflected portion of the signal emitted by each of the plurality of first emitters across at least a portion of the opening.

10. The debris monitoring system of claim 9 further comprising a controller configured to pulse the plurality of first emitters on and off and to pulse the plurality of second emitters on and off.

11. The debris monitoring system of claim 10 wherein the controller is further configured to sample of each of the first and second receivers synchronously such that a first sample of each receiver is taken when the plurality of first emitters and the plurality of second emitters are off, a second sample of each receiver is taken when the plurality of first emitters is on and the plurality of second emitters is off, and a third sample of each receiver is taken when the plurality of first emitters is off and the plurality of second emitters is on.

12. The debris monitoring system of claim 9 wherein the plurality of first emitters and the plurality of second emitters are arranged relative to one another such that the signals emitted by the plurality of first emitters intersect the signals emitted by the plurality of second emitters, the intersection being along at least a portion of the opening.

13. The debris monitoring system of claim 12 wherein the plurality of first emitters and the plurality of second emitters are arranged relative to one another such that the signals emitted by the plurality of first emitters intersect the signals emitted by the plurality of second emitters along a line substantially bisecting the opening.

14. The debris monitoring system of claim 9 wherein the plurality of first emitters and the plurality of second emitters are spaced relative to one another such that the signals emitted by the plurality of first emitters and the plurality of second emitters span substantially all of the area of the opening when all of the emitters from each of the plurality of first and second emitters are on.