RU54675U1 - OPTICAL-ACOUSTIC DEVICE FOR MEASURING THE OCTAN NUMBER OF GASOLINS - Google Patents

Abstract

The invention relates to the field of measuring equipment and can be used to measure the octane number of gasolines. The objective of the invention is to provide a device for rapid measurement of the octane number of gasoline. In accordance with the task, the claimed device contains a narrow-band laser with a tunable wavelength 1, a condenser 2, a measuring cell 3 with shut-off valves, a microphone 6, built into the wall of the measuring cell, a photodetector 7, an amplifier - U _{1 August} amplifier and - U _{February 9,} the laser modulation frequency generator 10, the output signal normalization block 11, information processing unit 12, the information processing and display unit 12, tuner 13 wavelength.

Description

The present invention relates to the field of measurement technology and can be used to measure the octane number of gasolines.

The closest to the proposed technical essence is a method for determining the octane number in a fuel mixture, which consists in transmitting a frequency from a source of infrared (IR) radiation in the zone of 0.8 to 2.6 μm through a cuvette with the test fuel and measuring the degree of absorption transmitted through the cuvette radiation frequencies (FR, application No. 2619624, Cl. G 01 N 33/26, 1989) and a device for its implementation, containing an IR radiation source, optical filters, photodetectors, a device for processing the received information and displaying the result s calculation on the display (patent No. 5, 225, 679, CL. G 01 N 21 / 35,1993).

However, the known method and device do not have a sufficiently high measurement accuracy due to the time variation of the parameters of infrared radiation and a photodetector having an analog structure, which ultimately affect the accuracy of determining the octane number.

The objective of the invention is to provide a device for rapid measurement of the octane number of gasolines with increased measurement accuracy.

In accordance with the task, the proposed device for measuring the octane number of gasolines contains a narrow-band laser with a tunable wavelength, a condenser, a measuring cell with shut-off valves, a microphone built into the wall of the measuring cell, a photodetector, an amplifier U ₁ and an amplifier U ₂ , a frequency generator

laser modulation, output signal rationing unit, information processing and indication unit, wavelength adjustment unit.

In FIG. Functional diagram of the device is presented. A device for measuring the octane number of gasolines comprises a narrow-band laser 1 with a tunable wavelength, a condenser 2, a measuring cell 3, to the ends of which are attached optically transparent windows (in the spectral range of measurement), shut-off valves 4 and 5, built into the measuring cell, microphone 6, built-in to the wall of the measuring cell 3, a photodetector 7, an amplifier - U ₁ 8 and an amplifier - U ₂ 9, a laser modulation frequency generator 10, an output signal rationing unit 11, an information and indication processing unit 12 and a wavelength adjustment unit s 13, the microphone output 6 is connected to the first input of the amplifier U ₁ 8, the output of the photodetector 7 is connected to the first input of the amplifier U ₂ 9, the second output of the laser modulation frequency generator 10 is connected to the second inputs of the amplifiers 10, the outputs of the amplifiers 8 and 9 are connected to the corresponding inputs of the normalization block of the output signal 11, the output of the normalization block of the output signal 11 is connected to the input of the information processing and display unit 12, the output of which is connected to the input of the wavelength tuner 13, the output of the wavelength tuner 13 is connected to the first input narrow-band laser 1, and to the second input of which is connected the first output of the laser modulation frequency generator 10.

The work of the proposed device is as follows.

In principle, the operation of the device is the absorption of infrared radiation in the range of 660-2600 nm in the environment of hydrocarbon fuel. A good correlation between absorption and the octane number is in the region of 896 nm, 932 nm and 1164 nm for the research octane number and, 930 nm, 940 and 1012 nm for the motor octane number (Analytical Chem. V.61,

p. 313-320). Frequency-modulated laser radiation 1 (the simplest pulsed laser mode) through a condenser 2 enters the measuring cell 3, into which the test fuel is poured through shut-off valves 4 and 5, the modulated laser radiation is passed through the cell filled with the analyzed fuel. If the laser radiation line coincides with the absorption band of the detected molecules, the fuel (gasoline) absorbs part of the laser radiation power, heats up and creates a pressure increase, which is an optical-acoustic signal (OA signal) that carries information about the concentration of molecules of gasoline components. Then, the OA signal is converted into an electrical signal using a microphone 6, placed in the measuring OA cell 3. From the output of the microphone 6, the signal enters the amplifier 8. In the linear absorption mode, the amplitude of the OA signal is proportional to the laser radiation power. Therefore, to exclude the influence of radiation fluctuations on the measurement accuracy, it is necessary either to stabilize the laser parameters, or, more simply, to use a second reference channel to register the radiation power U ₂ , the value of which is generated by the photodetector 7 due to the transmitted laser radiation through the measuring cell 3, and is amplified by an amplifier - U ₂ 9. The signals U ₁ and U ₂ are fed to the normalization unit of the output signal 11, for this the ratio U ₁ / U ₂ is determined and then the normalized signal is fed to the information processing unit and indicator nation. The modulation frequency generator 10 sets the laser operation mode and synchronizes the operation of amplifiers 8 and 9. The information processing and indication unit 12 controls the laser radiation wavelength adjustment unit 13, which in turn tunes the laser operation to a predetermined operation mode.

Claims (1)

The optical-acoustic device for measuring the octane number of gasolines contains a narrow-band laser with a tunable wavelength, a capacitor, a measuring cell with optically transparent windows (in the spectral range of measurement) attached to its ends, shut-off valves built into the measuring cell, and a microphone integrated into the measuring wall cells, a photodetector, an amplifier - U ₁ and an amplifier - U ₂ , a laser modulation frequency generator, an output signal rationing unit, an information and indication processing unit, and a length adjustment unit s wave output microphone connected to a first input of the amplifier U _1, the output of the photodetector is connected to the first input of the amplifier U _2, the second inputs of amplifier U ₁ and U ₂ is connected the second output of oscillator laser modulation frequency, amplifier outputs U ₁ and U ₂ are connected to respective the inputs of the output signal rationing unit, the output of the output signal rationing unit is connected to the input of the information processing and indication unit, the output of which is connected to the input of the wavelength adjustment unit, the output of the wavelength adjustment unit is connected to the first input Rinse the laser, and to a second input of which is connected a first generator output laser modulation frequency.