摘要:
A sensitivity-enhanced flow cell to be used in the determination of the differential refractive index increment of a sample fluid relative to a reference fluid is disclosed. The invention permits the use of smaller sample amounts without sacrificing overall sensitivity. Equally important, said improved How cell produces measurements of increased precision without requirement for increased sample amount. This is achieved by means of two chambers within said cell whose volumes are different. The sample fluid chamber is the smaller of the two with the reference fluid chamber constructed so that the incident illumination beam, upon passage through said sample chamber and displacement by the partition element located therebetween said sample and reference chambers, passes through said reference chamber without grazing any of the confining walls or striking corners of said sensitivity-enhanced flow cell. As the amount of deflection of said transmitted beam depends upon the refractive indices of the fluids relative to the transparent matter of which the containing cell is comprised, as well as the RI difference between said fluids themselves, the reference chamber is designed to transmit said incident light beam without grazing degradation thereof for all practical ranges of expected fluid and cell refractive indices.
摘要:
A cell for a walk-off refractometer is disclosed that permits measurement of the differential refractive index, DRI, between a sample fluid and a reference fluid. In addition, the new cell design permits the measurement of the refractive index, RI, of a fluid relative to the refractive index of the material comprising or surrounding the flow cell. Thus a single instrument may be used to measure separately the RI of a sample fluid and the DRI between a sample fluid and a reference fluid. The new flow cell contains two chambers, typical of a DRI instrument, but an asymmetric internal angle in either the sample or the reference chamber. By the provision of this structure, it is an objective of this invention to be able to measure the refractive index of a fluid relative to the refractive index of the material comprising the flow cell or relative to the medium surrounding the flow cell, either of which may be considered a measurement of the RI of the fluid. With the addition of mirror means, it is the further objective of this invention to improve its sensitivity. A further objective of the invention is to measure the asymmetric internal angle of the flow cell using well-characterized reference fluids.
摘要:
An improved differential refractometer incorporating a photodetector array is disclosed. Using a multi-element photo array provides the basis for measurement of differential refractive index values with a heretofore unattainable combination of sensitivity of measurement and concurrent range of measurement. Within the large dynamic range attainable, the detector structure provides equal sensitivity irrespective of deflection within the range. The transmitted light beam is tailored to provide a spatial variation of the light intensity at the array improving thereby the precision of measurement of its displacement. This in turn results in improved precision in the reported differential refractive index and in the calculation of the differential refractive index increment dn / dc . Integrating the detector array into the flow cell structure of the parent case results in a detector of exceptional sensitivity and range for sample quantities far smaller than required by conventional differential refractometers.
摘要:
An improved differential refractometer incorporating a photodetector array is disclosed. Using a multi-element photo array provides the basis for measurement of differential refractive index values with a heretofore unattainable combination of sensitivity of measurement and concurrent range of measurement. Within the large dynamic range attainable, the detector structure provides equal sensitivity irrespective of deflection within the range. The transmitted light beam is tailored to provide a spatial variation of the light intensity at the array improving thereby the precision of measurement of its displacement. This in turn results in improved precision in the reported differential refractive index and in the calculation of the differential refractive index increment dn / dc . Integrating the detector array into the flow cell structure of the parent case results in a detector of exceptional sensitivity and range for sample quantities far smaller than required by conventional differential refractometers.
摘要:
A cell for a walk-off refractometer is disclosed that permits measurement of the differential refractive index, DRI, between a sample fluid and a reference fluid. In addition, the new cell design permits the measurement of the refractive index, RI, of a fluid relative to the refractive index of the material comprising or surrounding the flow cell. Thus a single instrument may be used to measure separately the RI of a sample fluid and the DRI between a sample fluid and a reference fluid. The new flow cell contains two chambers, typical of a DRI instrument, but an asymmetric internal angle in either the sample or the reference chamber. By the provision of this structure, it is an objective of this invention to be able to measure the refractive index of a fluid relative to the refractive index of the material comprising the flow cell or relative to the medium surrounding the flow cell, either of which may be considered a measurement of the RI of the fluid. With the addition of mirror means, it is the further objective of this invention to improve its sensitivity. A further objective of the invention is to measure the asymmetric internal angle of the flow cell using well-characterized reference fluids.