DE2222202C3

DE2222202C3 - Photometer

Info

Publication number: DE2222202C3
Application number: DE19722222202
Authority: DE
Inventors: Paul Erwin Ariesheim Bucher (Schweiz); Picunko, Thomas, Bronxville, N.Y. (V.St.A.)
Original assignee: Union Carbide Corp
Current assignee: Union Carbide Corp
Filing date: 1972-05-05
Publication date: 1977-06-23

Description

F i g. 2 die zugehörige Auswertschaltung.F i g. 2 the associated evaluation circuit.

Das dargestellte Fotometer umfaßt einen DrehtischThe photometer shown comprises a turntable

10, in dem entlang eines Kreises um die Drehachse mehrere Reagenzflüssigkeitskammern in Form von Küvettenll angeordnet sind. Jede Küvette 11 besitzt einen lichtdurchlässigen Abschluß, so daß Licht durch die Küvette hindurch strahlen kann. Bei dem Drehtisch 10 ist eine Glasscheibe 12 unter der Küvette 11 angeordnet und bildet deren Boden, und ein nicht dargestellter, transparenter oberer Teil der Küvette 11 erlaubt den Durchgang einss Lichtstrahls 13 von einer Lichtquelle 14 durch die Küvette zu einem herkömmlichen Photomultiplier-Detektor 15.10, in which along a circle around the axis of rotation several reagent liquid chambers in the form of Küvettenll are arranged. Each cuvette 11 has a translucent seal so that light can pass through the cuvette can shine through. In the case of the turntable 10, there is a glass pane 12 under the cuvette 11 arranged and forms the bottom thereof, and a transparent upper part of the cuvette 11 (not shown) allows the passage of a light beam 13 from a light source 14 through the cuvette to a conventional one Photomultiplier detector 15.

Eine in dem Drehtisch 10 vorgesehene abnehmbare Probenüberführungsscheibe 16 weist eine Vielzahl von Ausnehmungen 17a, 17/> und 17c für die Aufnahme von Proben, Reagenzien und dergleichen auf. Die Ausnehmungen 17«, 17 ft und 17c stehen mit der Küvette 11 durch einen Überführungskanal 18 in Verbindung. Im Betrieb kann eine zu analysierende Probe in eine Ausnehmung 176 und ein Reagens in eine zugeordnete Ausnehmung 17λ eingebracht werden. Wenn der Drehtisch 10 durch Rotation der Antriebseinheit 19 in Drehung versetzt wird, fließt das Reagens in die die Probe enthaltende Ausnehmung 17 b und mischt sich mit tier Probe. Das Gemisch strömt dann in eine Uberführungsausnehmung 17c und anschließend durch den Überfuhrungskanal 18 in die KüvetteA detachable sample transfer disk 16 provided in the turntable 10 has a plurality of recesses 17a, 17 /> and 17c for receiving samples, reagents and the like. The recesses 17 ″, 17 ft and 17 c are connected to the cuvette 11 through a transfer channel 18. In operation, a sample to be analyzed can be placed in a recess 176 and a reagent can be placed in an associated one Recess 17λ are introduced. When the turntable 10 by rotation of the drive unit 19 is set in rotation, the reagent flows into the sample-containing recess 17 b and mixes with animal sample. The mixture then flows into a transfer recess 17c and then through the transfer channel 18 into the cuvette

11. In einem Mchrstationenphotometrie-Analysator, z. B. einem Analysator mit 30 Kiivctten und 3D Sätzen von mit den Küvettcn in Verbindung stehenden Aufnahmckanimern oder Ausnehmungen kann eine Bezugsflüssigkeit, z. B. destilliertes Wasser, für eine Küvette eingeteilt werden, während die zu analysierenden Proben für die anderen Küvettcn eingeteilt werden können. Die die Bezugsflüssigkeit enthaltende Kii-11. In a micro-station photometry analyzer, e.g. B. an analyzer with 30 cells and 3D sentences of receptacles associated with the cuvettes or recesses can be a reference liquid, e.g. B. distilled water for a cuvette while the samples to be analyzed are allocated to the other cuvettes be able. The child containing the reference liquid

vette wird dann als Standard verwendet, gegen den jede der übrigen Proben einzeln gemessen wird.vette is then used as a standard against which each of the remaining samples is measured individually.

Wie aus F i g. 2 ersichtlich ist, wird das Ausgangssignal des Photomultiplierdetektors 15 an eine Klemme 30 der dargestellten Schaltungsanordnung angelegt. Das an die Klemme 30 angelegte Signal besteht aus einer Reihe elektrischer Impulse, darunter einem Bezugsimpuls. Ein logarithmischer Verstärker 32 empfängt die bei 30 angelegten elektrischen Impulse und erzeugt bei 34 ein Ausgangssignal in Form von Impulsen. Die bei 34 erzeugten Impulse werden an eine Eingangsklemme 36 eines Differentialverstärkers 38 angelegt. Die bei 34 erzeugten Impulse werden außerdem über einen Widerstand 35 an eine Klemme 40 eines Feldeffekttransistors 42 angelegt. Der Transistor 42 ist jedoch nur leitend, wenn ein Signal an eine Klemme 44 angelegt wird. Ein solches Signal in Form eines zeitlich abgestimmten Steuerimpulses wird in Übereinstimmung mit dem bei 34 auftretenden Bezugsimpuls an die Klemme 44 angelegt. Auf diese W~ise wird ein Kondensator 46 auf den Wert des Bezugsimpulses geladen, und dieser Wert wird über einen Trennverstärker 47 an eine Eingangsklemme 48 des Differentialverstärkers 38 angelegt. Das Ausgangssignal des Differentialverstärkers 38 besteht daher in einer Reihe von Impulsen, dieAs shown in FIG. 2 can be seen, the output signal of the photomultiplier detector 15 to a Terminal 30 of the circuit arrangement shown is applied. The signal applied to terminal 30 consists of a series of electrical pulses including a reference pulse. A logarithmic amplifier 32 receives the electrical pulses applied at 30 and generates an output signal at 34 in the form of impulses. The pulses generated at 34 are applied to an input terminal 36 of a differential amplifier 38 created. The pulses generated at 34 are also through a resistor 35 to a Terminal 40 of a field effect transistor 42 is applied. The transistor 42 is only conductive when a Signal is applied to a terminal 44. Such a signal in the form of a timed control pulse is applied to terminal 44 in accordance with the reference pulse occurring at 34. In this way, a capacitor 46 is charged to the value of the reference pulse, and this The value is applied to an input terminal 48 of the differential amplifier 38 via an isolating amplifier 47. The output of differential amplifier 38 therefore consists of a series of pulses which

ίο die Differenz zwischen dem Bezugsimpuls und allen bei 34 auftretenden Impulsen darstellen. Diese Impulse an einem Ausgang 50 des Differentialverstärkers 38 können an ein herkömmliches Oszilloskop oder ein anderes Gerät angelegt werden, das Impulse aufzeichnet, die die Lichtabsorptionsfähigkeit der jeweiligen in den Küveiten befindlichen Proben anzeigen. ίο the difference between the reference pulse and all represent at 34 occurring pulses. These pulses at an output 50 of the differential amplifier 38 can be connected to a conventional oscilloscope or other device that uses the Impulse records, which indicate the light absorption capacity of the respective samples in the cuvettes.

Hierzu 1 Blatt Zeichnungen1 sheet of drawings

Claims

Claim:

Photometer with a light source, a photo receiver arranged in the beam path of the light source, a turntable which has a plurality of reagent liquid chambers arranged along a circle around the axis of rotation and with these in Has connected sample liquid chambers which, when the turntable rotates, the »o Can be introduced one after the other into the beam path, and with one connected to the photoreceiver Evaluation circuit for generating the light permeability of one of the sample liquid chambers related, the light transmission corresponding to one of the other chambers Signals, characterized that the evaluation circuit has a logarithmic circuit (32) connected to the photoreceiver (15) and a differential amplifier (38) that the one input (36) of the Differential amplifier (38) is directly connected to the output of the logarithmic circuit (32) and that the other input (48) of the differential amplifier (38) is connected to a memory device (46) connected via a controllable switch (40, 42, 44) then each with the output the logarithmic circuit (32) is connected when the one of the sample liquid chambers (11) is in the beam path.

3535

The invention relates to a photometer with a light source, one in the beam path of the light source arranged photoreceiver, a turntable, the several arranged along a circle around the axis of rotation Reagent fluid chambers and sample fluid chambers connected to them which can be introduced into the beam path in sequence when the turntable rotates, and with an evaluation circuit connected to the photoreceiver to generate light transmission related to one of the sample liquid chambers, the light transmittance of each of the signals corresponding to other chambers.

A photometer of this type is known (US-PS 35 55 284). Here those are proportional to the light intensity Measurement signals from the photoreceiver are displayed directly via a peak value meter. In front The actual measurement is carried out from a reference sample in one of the sample liquid chambers (e.g. distilled water) measure a reference value via the peak voltmeter to which then all other MoHwertc can be obtained. at This known photometer is therefore not a direct indication of the respective sample liquid value possible; a conversion to the reference value must always be carried out by the user.

There is also a photometer known (DT-OS 21 37 332), in which in separate samples one after the other Reference signals and measurement signals are obtained. which is then switched via a time division multiplex evaluated and compared with each other. The output signals of the photoreceiver are used for this purpose one common. Logarithmic circuit and then one input on the one hand and on the other hand via a control circuit which forms a reference value from the respective measured value, the other Input of a differential amplifier fed. This known evaluation circuit is for photometers of the type mentioned at the beginning cannot be used, since here measurement signals and reference signals are in separate samples must be generated one after the other.

It is therefore the object of the invention to provide an evaluation circuit for a photometer of the type mentioned at the beginning Art to create, which is very simple in structure and insensitive to interference and which is still immediate Allows the individual sample measurement values to be displayed in relation to a reference value.

Based on a photometer of the type mentioned at the beginning, this object is achieved according to the invention solved by the features of the characterizing part of the claim.

The evaluation circuit according to the invention makes it possible that in each case directly from each individual Measurement signal of a sample and the respective reference signal for the immediate display can be derived can. The evaluation circuit according to the invention is very simple in structure and therefore also insensitive to interference and still ensures a very accurate immediate display.

The invention is illustrated below with reference to schematic drawings of an exemplary embodiment explained in more detail. It shows

Fig. 1 shows the mechanical part of a photometer and