US 4,308,231 A · Optical timing and A/D conversion method and apparatus

Abstract

An optical timing and A/D conversion method and apparatus for converting analog signals obtained by movement of a plurality of reaction vessels relative to one or more beams of light from analog to digital signals. The sample signals are obtained each time a reaction vessel passes through a beam of light. The converted digital signals indicate the absorbance of the respective vessels and their contents. Each of the reaction vessels or cuvettes has translucent wall portions providing a radiation path therethrough for the light beams which may be monitored by photometer means in a chemical reaction analyzer. The vessels are repeatedly passed through the light beams of the photometer means as chemical reactions take place therein, the purpose being to monitor the changes in the reaction of the fluids therein by measuring the changes in the absorbance of the vessel and fluids. The sample interval of the analog signal is repeatable for each vessel for each light beam and may be shifted to select the best portion of the analog signal generated as the vessel passes through the particular light beam. The A/D conversion also may eliminate the dark sample or noise error between the light beams and the reaction vessels and may eliminate the variations in the sample signals caused by changes in the rate of relative movement between the beams and vessels and changes in the velocity of the rotating beam.

Claims32

Dependent claims

Apparatus of the type in which a reaction effect in a cuvette is measured by passing a beam of radiant energy through said cuvette and detecting the degree of absorbance of the radiant energy as a measure of the said reaction effect,

in which structure is provided for optimizing the period of time during which the measurement is taking place relative to the alignment of the beam and cuvette to obtain data concerning said measurement, said structure comprising:
A. a carrier having a plurality of at least partially transparent cuvettes mounted thereon and each cuvette adapted to have an individual reaction sample therein to be subjected to said beam,
B. means for generating said beam and means responsive to the unabsorbed radiant energy of said beam after it has passed through a cuvette and reaction sample therein, if any, to produce a reaction effect signal,
C. means for moving the carrier and beam generating means relative to one another whereby to cause the beam to scan the cuvettes seriatim for producing a separate reaction effect signal each time said beam passes a cuvette, the duration of each reaction effect signal being related to the time required for the beam to scan the particular cuvette and having an amplitude related to the beam absorbance in said particular cuvette,
D. identification means associated with said carrier for producing signals identifying the respective cuvettes,
E. means for photoresponsively triggering the sampling of the reaction effect signal only when the beam and the center of each cuvette are in coincidence and for a predetermined time before and after coincidence, and
F. means for converting each reaction effect signal sample into respective data indicative of the absorbance of the reaction sample in said cuvette and the portions of said cuvette through which said beam has passed individual to the identifying signal of said cuvette.

4 more elements

A method of obtaining data relating to the absorbance of a beam of radiant energy of a predetermined wavelength through a plurality of at least partially transparent reaction vessels, each vessel containing a reaction sample of an individual character relative to the other reaction samples in the other reaction vessels, the beam of radiant energy having an optical axis, the beam being passed relative to all of the vessels to scan the same seriatim, the amount of energy remaining in the beam after passing through each cuvette being measured and adapted to be utilized to derive the said absorbance data, the method comprising:

A. repeatedly passing said reaction vessels through said optical axis in a plurality of cycles,
B. generating a train of sample signals by said passage, each signal being related to the absorbance of a respective vessel and its contents if any, the sample signals each being generated when the sample vessel individual thereto is substantially coincident with said optical axis,
C. moving a plurality of window generating means for photoresponsive sampling from said signals, equal in number to said sample vessels and each being individual to a vessel, in synchronism with the vessels relative to said optical axis,
D. generating an integrating signal defined by said at least one window generating means as it moves relative to said optical axis,
E. gating each sample signal with the integrating signal individual thereto, and
F. generating data from the gated sample signals.

3 more elements

Dependencies are inferred from the claim text.

Optical timing and A/D conversion method and apparatus

Life of this patent

Optical timing and A/D conversion method and apparatus

Life of this patent

Abstract

Claims32