SU1427189A1 - Spectrophotometer - Google Patents

Abstract

The invention relates to the field of optical spectral instrumentation. The aim of the invention is to increase the productivity and accuracy of measurements. The radiation from the radiation source passes the monochromator, the cuvette and is recorded by the photodetector. The signal of the photodetector enters the recording device. The cuvette is filled with vehicle using a filling device. With the help of the sensor, the level of the meat in the cuvette is monitored. To empty the cuvette, there is an electromagnet valve. The level sensor gives a signal to the control unit, which gives a signal to stop liquid presses} - to the filling device. The control unit also produces stringers entering the electromagnet valve and recording device. To determine the end of the measurement, a recording device is connected to the control unit. The analysis time will only smear from the time the sample is supplied to the L device, since the time for emptying the cuvette is insignificant, 1 sludge. with y

Description

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This invention relates to optical spectral instrumentation.

The purpose of the invention is to improve the performance and accuracy of measurements.

The drawing shows a block diagram of a spectrophotometer.

The device contains a radiation source 1, a monochromator 2, a cuvette 3, a photodetector 4, a recording device 5, an electromagnetic valve 6, a level sensor 7, an inlet 8, a filling device 9, a control unit 10. Block 10 consists of an inverter 11, triggers 12 and 13, a logic element OR 14, a transistor switch 15, an optocoupler 16, a thyristor switch 17, a single-oscillator 18, a logic element .OR 19, a transistor switch 20, a single-oscillator 215 buttons 22 Measurement and buttons 23 Flushing.

The device works as follows.

In the initial state, the cuvette 3 is washed, the filling device 9 is turned off, the solenoid valve 6 is closed, the suction nozzle 8 is immersed in the container and the test solution.

When the button 22 is pressed, Measurement 9 turns on the device, creating a vacuum in the cuvette 3. At the same time, the test sample is sucked into the cuvette 3 up to the level of contact with the electrodes of the sensor 7. The vacuum in cuvette 3 disappears and the spectrophotometer is switched to the Measurement mode. After the measurement results have been output, the control unit 10 will issue a command to open the electromagnetic valve 6.

The need to turn off the device 9 for emptying the cuvette 3 is due to the fact that due to the created vacuum, sample leakage is possible

The control unit 10 operates in the following manner.

In the initial state, the triggers are set to the state O, both transistor switches 15 and 20 are closed. Since the cuvette 3 is empty, a signal 1 is present at the output of the inverter 11. When the button 23 is pressed, flushing, the S input of the trigger 13 receives a signal 1, which translates

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trigger 13 in one state. Signal 1, passing through the logic element OR 14, opens a transistor switch, 15, which, in turn, opens the thyristor opron 16, which triggers the device 17 thyristor switch 17. As soon as the cuvette 3 is filled, the liquid closes the contacts of the sensor 7 and The output of the inverter 11 is Wits signal O, respectively, at its output WITS signal 1. This signal, having arrived at the R-flip-flop 13, returns it to its original state, the device 9 turns off. The transition of the signal at the output of the trigger 13 from state 1 to state O triggers the action of the one-shot 18, which extracts a pulse of positive polarity of a given duration. This impulse, passed through the logical element OR 19, opens the transistor switch 20, which turns on the solenoid valve 6.

When the button 22 is pressed. The measurement turns over the trigger 12 and turns on the device 9. As the cuvette 3 is filled, the trigger 12 returns to the initial state, the device 9 turns off.

The transition of trigger 12 from state 1 to state O is triggered by a one-shot 21, which produces a positive pulse, which includes a recording device 5 of the spectroinformat. As soon as the measurement process ends from the recording device 5, the output pulse of the logical element OR 19 will receive a positive pulse of a specified duration. The pulse passed through the logical element OR, opens the transistor switch 20, which includes a solenoid valve 7.

The duration of the pulses generated by the single vibrators 18 and 21 is chosen such that during the passage of the pulse, the cuvette 3 has time to completely empty.

The advantage of the spectrophotometer is that the analysis time practically depends only on the time the sample is delivered to the instrument, since the emptying time of the cell is insignificant, and in the case of full automation it can be commensurate with the measurement time of the optical properties of the liquid.

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Claims (1)

Claim A spectrophotometer containing an optically coupled radiation source, a monochromator, a cuvette equipped with a sample vessel and a filling device, and a photodetector, as well as a recording device connected to the first input with a photodetector, and a control unit connected to the filling device with the first output, characterized in that , in order to increase the productivity and accuracy of measurements, the cuvette additionally contains a level sensor and 5 solenoid valve, wherein the level sensor is connected to the first input of the control unit, the second output of the control unit is connected to the electromagnetic valve, the third output 10 of the control unit is connected to the second input of the recording device, the output of which is connected to the second input of the control unit.