Postacquired spectrophotometers

A postacquired spectrophotometer, for use with a sample and a reference, said spectrophotometer comprising:

• a filter unit defining an axis of rotation, said filter unit having a plurality of designated sites and a plurality of dark sites disposed in substantially uniform angular relation to said axis, said designated sites and said dark sites being disposed in alternation, alternating ones of said designated sites having apertures, said filter unit having a plurality of actuator pairs each said pair having an integration actuator and a clamping actuator, said actuators being disposed in substantially uniform radial relation to said axis, said integration actuators each being associated with a respective said designated site,
• filters, each said filter covering a respective said aperture, said filters each transmitting only light of preselected wavelengths,
• a main member coaxial with said filter unit, said main member having sample and reference beam paths, said beam paths being intersected by said sites, said main member having an actuator sensor disposed in operative relation to said actuators, said actuator sensor generating an integration actuator signal upon alignment with each said integration actuator and a clamping actuator signal upon alignment with each said clamping actuator,
• a drive continuously rotating said filter unit relative to said axis and said beam paths,
• a detector for producing a signal responsive to light received,
• a light distribution system directing light separately from said sample and reference to respective said beam paths, and from said beam paths to said detector,
• means for processing said signals, said means for processing further comprising a clamping circuit, a plurality of integrators, and a demultiplexer, said clamping circuit in response to each said clamping actuator signal setting a restoration signal proportional to said detector signal, said clamping circuit in response to each said integration actuator signal clamping said detector signal to said restoration signal, said demultiplexer distributing said clamped detector signal to said integrators, said demultiplexer having a single output, said output advancing from one of said integrators to another in repeating sequence in response to one of the members of each said pair of actuator signals, and
• means for repeatedly allocating each integrator to the same filter and beam path.

A postacquired spectrophotometer, for use with a sample and a reference, said spectrophotometer comprising:

• a filter unit defining a longitudinal axis, said filter unit being movable along said longitudinal axis, said filter unit having a plurality of designated sites and a plurality of dark sites disposed in uniform spaced relation to said axis, said designated sites and said dark sites being disposed in alternation, alternating ones of said designated sites having apertures and filters covering said apertures, said filter unit having a plurality of actuator pairs each said pair having an integration actuator and a clamping actuator, said actuators having a substantially uniform relation to said axis, said integration actuators each being associated with a respective said designated site,
• a main member coaxial with said filter unit, said main member having sample and reference beam paths, said beam paths being intersected by said sites, said beam paths each having a cross-section at said filter unit interposable within each said site, said main member having an actuator sensor disposed in operative relation to said actuators, said actuator sensor generating an integration actuator signal upon alignment with each said integration actuator and a clamping actuator signal upon alignment with each said clamping actuator,
• a drive for continuously reciprocating said filter unit along said axis relative to said beam paths,
• a detector for producing a signal responsive to light received,
• a light distribution system directing light separately from said sample and reference to respective said beam paths, and from said beam paths to said detector, and
• means for processing said signals, said means for processing further comprising a clamping circuit, a plurality of integrators, and a demultiplexer, said clamping circuit in response to each said clamping actuator signal setting a restoration signal proportional to said detector signal, said clamping circuit in response to each said integration actuator signal clamping said detector signal to said restoration signal, said demultiplexer distributing said clamped detector signal to said integrators, said demultiplexer having a single output, said output advancing from one of said integrators to another in repeating sequence in response to one of the members of each said pair of actuator signals.

A multiple sample spectrophotometer, for use with a plurality of samples and at least one reference, said samples each being paired with a reference, said spectrophotometer comprising

• a filter unit movable relative to an axis of movement, said filter unit having a plurality of designated sites and a plurality of dark sites disposed in substantially uniform relation to said axis, said designated sites and said dark sites being disposed in alternation, alternating ones of said designated sites having apertures and filters covering said apertures, said filters each transmitting only light of preselected wavelengths, said filter unit having a plurality of actuator pairs each said pair having an integration actuator and a clamping actuator, said actuators being disposed in substantially uniform relation to said axis, said integration actuators each being associated with a respective said designated site,
• a main member coaxial with said filter unit, said main member having a plurality of pairs of beam paths, said beam paths being intersected by said filter unit sites, said main member having an actuator sensor disposed in operative relation to said actuators, said actuator sensor generating an integration actuator signal upon alignment with each said integration actuator and a clamping actuator signal upon alignment with each said clamping actuator,
• a drive for continuously moving said filter unit relative to said axis and said beam paths,
• at least one detector for producing a signal responsive to light received,
• a light distribution system directing light separately to and from each said sample and reference pair, and to and from associated said beam paths, and to each said detector, and
• means for processing said detector signals, said means for processing further comprising for each said detector:
• a clamping circuit, a plurality of integrators, and a demultiplexer, said clamping circuit in response to each said clamping actuator signal setting a restoration signal proportional to said detector signal, said clamping circuit in response to each said integration actuator signal clamping said detector signal to said restoration, said demultiplexer distributing said clamped detector signal to said integrators, said demultiplexer having a single output, said output advancing from one of said integrators to another in repeating sequence in response to one of the members of each said pair of actuator signals.