Apparatus for measuring the optical absorbency of samples of liquids, method and reaction container for its implementation
View Patent ↗Apparatus for measuring the optical absorbency of samples of liquids, method and reaction container for its implementation. The apparatus comprises a receiving body for receiving the reaction containers carrying the samples to be analyzed, with means for causing each of the reaction containers to be passed through by a luminous signal of controlled wavelength, having means for conducting it to a scanning head where the luminous signals are picked up by a single CCD sensor, constituting a digital processing system for evaluating the absorbency of the corresponding sample.
1. A method for measuring optical absorbency of samples, comprising the steps of:
(a) obtaining one or more samples;
(b) individually placing each sample into a separate reaction container, wherein each reaction container has two windows frontally limiting the chamber;
(c) passing a luminous signal through the sample and the window and into a sample optical fiber corresponding to each container;
(d) directing the sample optical fibers through a scanning head that supports and positions the fibers; wherein the scanning head defines a matrix of lines and columns, wherein the point of arrival of each sample optical fiber does not coincide with the point of arrival of any other sample optical fiber in line or column, and the distance between the sample optical fibers is maximized;
(e) using a single sensor to simultaneously measure optical intensities of the luminous signals emitted from each sample optical fiber exiting the scanning head; and
(f) calculating optical absorbency of each sample using the measured intensities.
2. The method of claim 1 wherein the optical intensities are measured at the scanning head at time points separated by a predefined fixed time.
3. The method of claim 1 , wherein the optical intensities are measured at the scanning head using different acquisition times directed by an external control system.
4. The method of claim 3 wherein the acquisition times selected are the ones that do not cause saturation at the sensor.
5. The method of claim 1 , wherein the sensor comprises pixels corresponding to the points in the matrix that coincide with the positions of the luminous signals emitted from each sample optical fiber in the scanning head; and wherein the intensity of each sample optical fiber is measured with a mathematical operation of the pixels intensity corresponding to each point of each acquisition time selected.
6. The method of claim 1 , wherein the singe sensor is composed of elements sensitive to light and disposed matricially.
7. The method of claim 3 , wherein different periods of acquisition time are combined in order to define a plurality of scales of measurement which, overlapped, cover a wide dynamic range.
8. The method of claim 1 , further comprising the step of passing the luminous signal through different grey filters having an absorbency in the dynamic range, and into a reference optical fiber.
9. The method of claim 8 , further comprising the step of:
directing the reference optical fibers through a scanning head that supports and positions the fibers;
wherein the scanning head defines a matrix of lines and columns, wherein the point of arrival of each reference optical fiber does not coincide with the point of arrival of any other reference optical fiber in line or column, and the distance between the reference optical fibers is maximized.
10. The method of claim 9 , wherein the simultaneously measured intensities comprise the intensity of the sample optical fibers and the intensity of the reference optical fibers for further comparison between them in order to correct the drift in the luminous signal.
11. The method of claim 1 , wherein calculation of the optical absorbency comprises comparing the measured intensities to the optical intensity of a control sample having known absorbency.
12. The method of claim 11 , wherein the control sample is water.