Devices and methods for determining the density of insulation

1. A device for determining the density of insulation, the device comprising:

a probe configured to be inserted into insulation such that the probe contacts the insulation;

a first actuator configured to cause the probe to oscillate within a first plane;

a first sensor configured to sense the oscillation of the probe within the first plane;

a second actuator configured to oscillate the probe in a second plane that is perpendicular to the first plane;

a second sensor configured to sense oscillation of the probe within the second plane, the configured to generate a signal that represents the displacement and/or velocity of the probe within the second plane with respect to time; and

a control system configured to cause the first actuator and the second actuator to oscillate the probe,

the first sensor and the second sensor each being configured to generate a signal that represents the density of insulation, and

the control system is configured to use the generated signals to determine the density of insulation.

2. The device of claim 1 , wherein the probe comprises a non-magnetic material.

3. The device of claim 1 , further comprising a first base component, wherein the probe is coupled to the first base component at a first end of the probe and configured to oscillate at a second end of the probe.

4. The device of claim 1 , wherein the sensor comprises a coil of wire that defines a gap, and wherein the probe comprises a magnetic component that is configured to move within the gap and is magnetically coupled to the coil of wire.

5. The device of claim 1 , wherein the control system is configured to cause the actuator to oscillate the probe within the insulation until the oscillation of the probe reaches a substantially steady state amplitude, and wherein the signal represents the oscillation of the probe after the oscillation reaches the substantially steady state amplitude.

6. The device of claim 1 , wherein the control system is configured to use the signal to determine the density of insulation by:

rectifying the signal;

integrating the rectified signal over a predetermined duration after onset of oscillation of the probe to determine an amount of oscillation energy absorbed by the insulation; and

comparing the amount of oscillation energy absorbed by the insulation to an amount of oscillation energy that is absorbed in a reference substance during the predetermined duration when the probe oscillates in air.

7. The device of claim 1 , wherein the signal of the first sensor represents displacement and/or velocity of the probe relative to the sensor within the first plane with respect to time, and the signal of the second sensor represents the displacement and/or velocity of the probe within the second plane with respect to time.

8. A method for determining the density of insulation, the method comprising:

placing a probe into contact with the insulation;

causing, via a first actuator, the probe to oscillate within a first plane while in contact with the insulation; and

generating, via a first sensor configured to sense oscillation of the probe within the first plane, a signal that represents displacement and/or velocity of the probe within the first plane with respect to time;

causing, via a second actuator, the probe to oscillate within a second plane that is perpendicular to the first plane; and

generating, via a second sensor configured to sense oscillation of the probe within the second plane, a signal that represents displacement and/or velocity of the probe within the second plane with respect to time; and

using the generated signal to determine the density of insulation.

9. The method of claim 8 , wherein the insulation comprises fibrous insulation material.

10. The method of claim 8 , wherein the probe comprises a non-magnetic material.

11. The method of claim 8 , wherein placing the probe into contact with the insulation comprises placing the probe such that at least an end of the probe is surrounded by the insulation.

12. The method of claim 8 , wherein using the signal to determine the density of insulation comprises determining the density of insulation based on known characteristics of the insulation.

13. The method of claim 12 , further comprising:

receiving input, from an input device, representing the known characteristics of the insulation; and

using the received input to determine the density of insulation.

14. The method of claim 8 , wherein causing the probe to oscillate comprises causing the actuator to impart an oscillatory driving force to the probe via the actuator until the oscillation of the probe reaches a substantially steady state amplitude, and wherein the signal represents the oscillation of the probe after the oscillation reaches the substantially steady state amplitude.

15. The method of claim 8 ,

wherein the actuator comprises a first electromagnet that is positioned on a first side of the probe and a second electromagnet that is positioned on a second opposing side of the probe, and

wherein causing the probe to oscillate via the actuator while in contact with the insulation comprises alternatingly:

repelling or attracting, via the first electromagnet, the probe toward the second electromagnet, and

repelling or attracting, via the second electromagnet, the probe toward the first electromagnet.

16. The method of claim 8 , wherein the insulation is fibrous insulation disposed within a wall cavity of a building.

17. The method of claim 16 , wherein placing the probe into contact with the fibrous insulation in the cavity comprises inserting the probe through a wallboard bounding the cavity.

18. The method of claim 16 , wherein placing the probe into contact with the fibrous insulation in the cavity comprises inserting the probe through a paper or fabric disposed in front of the fibrous insulation.

19. The method of claim 16 , wherein placing the probe into contact with the fibrous insulation comprises placing the probe such that at least an end of the probe is surrounded by the fibrous insulation.

20. The method of claim 16 , wherein using the signal to determine the density of fibrous insulation comprises determining the density of fibrous insulation based on known characteristics of the fibrous insulation.

21. The method of claim 20 , further comprising:

receiving input, from an input device, representing the known characteristics of the fibrous insulation; and

using the received input together with the signal to determine the density of fibrous insulation.