Retroreflective systems for remote readout

Claim 2

A sensing device for sensing an environmental factor, said device comprising: reflective means for reflecting light; sensing means having an initial optical absorption capacity and being disposed in a substantially fixed orientation with respect to the reflective means for (i) sensing a presence of the environmental factor, (ii) experiencing a change in optical absorption capacity responsive to said environmental factor, and (iii) transmitting and attenuating light; wherein said reflective means is disposed in a facing alignment with respect to the sensing means such that light which is caused to pass through said sensing means is reflected by said reflective material; wherein the reflective means comprises retroreflective means for reflectively redirecting light from a first direction to a second direction substantially opposite the first direction and thus along a same movement path but opposite in direction.

Claim 3

The sensing device as defined in claim 1, wherein the sensing means is operable as defined in claim 1 without utilizing an external power source.

Claim 4

The sensing device as defined in claim 1, wherein the reflective means comprises a layer of retroreflective material and the sensing means comprises a layer of environmentally-sensitive material which is chemically reactable with the environmental factor, said retroreflective layer and said sensing layer being disposed in a parallel, facing relationship, said device further comprising: sealing means for sealing off at least a portion of the sensing layer from exposure to a surrounding environment such that said portion is prevented from experiencing a change in optical absorption capacity responsive to said environmental factor.

Claim 5

A sensing device for sensing an environmental factor, said device comprising: reflective means for reflecting light; sensing means having an initial optical light-scattering capacity and being disposed in a substantially fixed orientation with respect to the reflective means for (i) sensing a presence of the environmental factor, (ii) experiencing a change in optical light-scattering capacity responsive to said environmental factor, and (iii) transmitting and attenuating light; wherein said reflective means is disposed in a facing alignment with respect to the sensing means such that light which is caused to pass through said sensing means is reflected by said reflective material.

Claim 6

A sensing device for sensing an environmental factor, said device comprising: reflective means for reflecting light; sensing means having an initial optical light-scattering capacity and being disposed in a substantially fixed orientation with respect to the reflective means for (i) sensing a presence of the environmental factor, (ii) experiencing a change in optical light-scattering capacity responsive to said environmental factor, and (iii) transmitting and attenuating light; wherein said reflective means is disposed in a facing alignment with respect to the sensing means such that light which is caused to pass through said sensing means is reflected by said reflective material.

Claim 7

A sensing device for sensing an environmental factor, said device comprising: sensing means having an initial optical absorption capacity for (i) sensing a presence of the environmental factor, (ii) experiencing a change in optical absorption capacity responsive to said environmental factor, and (iii) transmitting and attenuating light; and reflective means disposed in a substantially fixed orientation with respect to the sensing means for reflecting light which passes through the sensing means; sealing means for sealing off a first portion of the sensing layer from exposure to a surrounding environment such that said first portion is prevented from experiencing a change in optical absorption capacity responsive to said environmental factor such that a second portion of the sensing layer remains exposed to said environment.

Claim 8

A sensing device for sensing an environmental factor, said device comprising: sensing means having an initial optical absorption capacity for (i) sensing a presence of the environmental factor, (ii) experiencing a change in optical absorption capacity responsive to said environmental factor, and (iii) transmitting and attenuating light; and reflective means disposed in a substantially fixed orientation with respect to the sensing means for reflecting light which passes through the sensing means; sealing means for sealing off a first portion of the sensing layer from exposure to a surrounding environment such that said first portion is prevented from experiencing a change in optical absorption capacity responsive to said environmental factor such that a second portion of the sensing layer remains exposed to said environment.

Claim 9

The sensing device of claim 5, wherein the sealing means comprises a plurality of separate, individual shield devices.

Claim 10

The sensing device of claim 6, wherein at least two of the plurality of separate, individual shield devices each comprise different material properties which experience different rates of natural degradation from exposure to the surrounding environment.

Claim 11

The sensing device of claim 5, further comprising: a light source means for directing light onto the sensing means; and a light-receiving means for receiving light reflected from the reflective means.

Claim 12

The sensing device of claim 8, further comprising: processing means operatively connected to the light-receiving means for measuring an extent of attenuation of the light reflected from the reflective means.

Claim 13

A sensing device for sensing an environmental factor, said sensing device comprising: sensing means having an initial optical absorption capacity for (i) sensing a presence of the environmental factor, (ii) experiencing a change in optical absorption capacity responsive to said environmental factor, and (iii) transmitting and attenuating light; and reflective means disposed in a substantially fixed orientation with respect to the sensing means for reflecting light which passes through the sensing means; sealing means for sealing off a first portion of the sensing layer from exposure to a surrounding environment such that said first portion is prevented from experiencing a change in optical absorption capacity responsive to said environmental factor such that a second portion of the sensing layer remains exposed to said environment; a light source means for directing light onto the sensing means; and a light-receiving means for receiving light reflected from the reflective means; wherein the light source means further comprises means for directing first and second beams of light onto the first and second portions of the sensing means, respectively, said device further comprising: processing means operatively connected to the light-receiving means for (i) comparing intensities of the first and second beams after they are reflected by the reflective means and (ii) computing a diagnostic ratio which is proportional to a ratio of said intensities, and (iii) determining from said diagnostic ratio a quantitative presence of the environmental factor.

Claim 14

A sensing device for sensing an environmental factor, said sensing device comprising: sensing means having an initial optical absorption capacity for (i) sensing a presence of the environmental factor, (ii) experiencing a change in optical absorption capacity responsive to said environmental factor, and (iii) transmitting and attenuating light; and reflective means disposed in a substantially fixed orientation with respect to the sensing means for reflecting light which passes through the sensing means; sealing means for sealing off a first portion of the sensing layer from exposure to a surrounding environment such that said first portion is prevented from experiencing a change in optical absorption capacity responsive to said environmental factor such that a second portion of the sensing layer remains exposed to said environment; a light source means for directing light onto the sensing means; and a light-receiving means for receiving light reflected from the reflective means; wherein the light source means further comprises means for directing first and second beams of light onto the first and second portions of the sensing means, respectively, said device further comprising: processing means operatively connected to the light-receiving means for (i) comparing intensities of the first and second beams after they are reflected by the reflective means and (ii) computing a diagnostic ratio which is proportional to a ratio of said intensities, and (iii) determining from said diagnostic ratio a quantitative presence of the environmental factor.

Claim 15

A sensing device for sensing an environmental factor, said sensing device comprising: sensing means having an initial optical absorption capacity for (i) sensing a presence of the environmental factor, (ii) experiencing a change in optical absorption capacity responsive to said environmental factor, and (iii) transmitting and attenuating light; and reflective means disposed in a substantially fixed orientation with respect to the sensing means for reflecting light which passes through the sensing means; sealing means for sealing off a first portion of the sensing layer from exposure to a surrounding environment such that said first portion is prevented from experiencing a change in optical absorption capacity responsive to said environmental factor such that a second portion of the sensing layer remains exposed to said environment; a light source means for directing light onto the sensing means; and a light-receiving means for receiving light reflected from the reflective means; wherein the light source means further comprises means for directing a beam of light onto the first and second portions of the sensing means and causing the reflective means to reflect said beam back through said first and second portion of said sensing means in the form of first and second return beams, respectively, said device further comprising: processing means operatively connected to the light-receiving means for (i) comparing intensities of the first and second return beams after they are reflected by the reflective means and (ii) computing a diagnostic ratio which is proportional to a ratio of said intensities, and (iii) determining from said diagnostic ratio a quantitative presence of the environmental factor.

Claim 16

A sensing device for sensing an environmental factor, said sensing device comprising: sensing means having an initial optical absorption capacity for (i) sensing a presence of the environmental factor, (ii) experiencing a change in optical absorption capacity responsive to said environmental factor, and (iii) transmitting and attenuating light; and reflective means disposed in a substantially fixed orientation with respect to the sensing means for reflecting light which passes through the sensing means; sealing means for sealing off a first portion of the sensing layer from exposure to a surrounding environment such that said first portion is prevented from experiencing a change in optical absorption capacity responsive to said environmental factor such that a second portion of the sensing layer remains exposed to said environment; a light source means for directing light onto the sensing means; and a light-receiving means for receiving light reflected from the reflective means; wherein the light source means further comprises means for directing a beam of light onto the first and second portions of the sensing means and causing the reflective means to reflect said beam back through said first and second portion of said sensing means in the form of first and second return beams, respectively, said device further comprising: processing means operatively connected to the light-receiving means for (i) comparing intensities of the first and second return beams after they are reflected by the reflective means and (ii) computing a diagnostic ratio which is proportional to a ratio of said intensities, and (iii) determining from said diagnostic ratio a quantitative presence of the environmental factor.