SU1733982A1 - Method of petrol identification - Google Patents

Abstract

The invention relates to assessing the quality of commercial gasolines in accordance with the octane number. The purpose of the invention is to improve the accuracy and reliability of the determination of the octane number. A sample of gasoline is placed in an optical cuvette. With the help of a light source. having a wavelength of 420 nm, the fluorescence of gasoline is excited; fluorescence intensities are measured at 425 and 450 nm. The product of electrical signals corresponding to both intensity of fluorescence is used to identify gasoline by octane. 1 il.

Description

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The invention relates to the study of the physicochemical properties of motor fuels, primarily gasoline, and can be used to identify and quickly measure the octane number and assess the quality of commercial gasoline both in the development of fuel mixtures under laboratory conditions and in arbitrary, including road in the presence of technical means that implement the method.

A known method for determining the octane number of gasoline mixtures is as follows. Using standard (guest) gasolines with a known octane number, determine the octane number of the mixtures based on them. The method is implemented on bulky and expensive laboratory installations and takes a long time.

Closest to the proposed technical solution is a method for identifying petroleum products, in particular gasolines, by the fluorescence spectrum. An ultraviolet laser with a wavelength of 337 nm was used to excite the fluorescence, and the fluorescence maximum for AI-93 and A-76 gasoline was observed at 480 nm. In this case, there was a difference in the spectra by intensity, in particular, at the maximum of the fluorescence intensity at a wavelength of 480 nm, which was used to identify petroleum products.

The use of an ultraviolet laser source for the excitation of fluorescence is inconvenient in that quartz optics that are transparent to ultraviolet are required to implement the method. Ultraviolet Fluorescence ExcitationXJ

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This makes it impossible to use an incandescent lamp as an excitation source due to the practical absence of ultraviolet in its spectrum. The fluorescence spectrum at the excitation radiation wavelength of 337 nm has one wide maximum, and the differences in fluorescence levels at the maximum, although they allow to distinguish oil products from one another, for example AI-93 and A-76 gasolines, but not sufficient to identify them by octane number .

The purpose of the invention is to simplify the means of implementing the method and to improve the accuracy and reliability of determining the octane number of gasoline.

This goal is achieved in that according to the method of identifying gasolines, including excitation and registration. Gasoline suspension, conversion of fluorescence into electrical signals by g-signals, the magnitude of which identifies, gasoline fluorescence is excited by radiation with a wavelength of 420 nm, and intensity signals are recorded at 425 and 450 wavelengths; / amplitude of the amplitudes of the electric i.-, 1. cale, corresponding to both ino-logos, is judged on the octane number

The guide is carried out as follows: m

, enzin is placed in a spectrophi - Lm / c cuvette and 1 g of ip fluorescence is determined. At the same time, fluores- i, H (g of gasoline is excited with radiation from; in and, - waves of 420 nm, for which use 1 Exciter or interferometer, interfering ion filter with maximum I, 4/0 nm. For identification j TQ fluorescence spectrum using o / u 3vrOT maxima of fluorescence intensity at 425 and 450 nm, rb-patterns in the spectra of commodity benches. The fluorescence intensity is recorded at 425 and about nm for which photosensors are used with sufficient sensitivity, and any possible ways to increase the sensitivity, for example The circuitry of the light by the circuit engineering methods, the hemnegun amplitudes of the electrical signals constituting both fluorescence intensities, is carried out by multiplying or balancing with the multiplier and on the scale of ind. 1 o. i :: g Di v a y t corresponding evo - -JPCIO

The drawing shows a functional diagram of the device that implements the method of identification of gasoline.

Quartz cuvette 1 serves to place a sample of the gasoline under investigation. The fluorescence-exciting radiation enters the cell from the radiation source 2 through the interference filter 3 with a transmission maximum at a wavelength of 420

0 nm. Two other interference filters 4 and 5 with transmission maxima at wavelengths of 425 and 450 nm produce fluorescence light of corresponding wavelengths, falling on photodetectors 6 and 7,

5 electrical outputs of which amplify the amplifiers 8 and 9. The balance modulator 10 serves for analog multiplication of the amplitudes of the output electric signals of both amplifiers, and

0 indicator 11 gives the value of the output electric signal of the balanced modulator corresponding to the value of the octane number. A differential circuit serves for balancing the measuring system.

5 12 with index 13 zero. The balancing is carried out at one of the interference filters 4 and 5 from the optical path by adjusting the gain of one of the amplifiers 8 or 9.

0 To implement the method, it is necessary to calibrate the output electric signal of the balanced modulator by octane number. For calibration, a sample of gasoline with a known octane number, nz5, an example of the brand AI-93 GOST2084-66, is placed in the cuvette of the device and irradiated with light with a wavelength of 420 nm. Next, the fluorescence intensity of the gasoline sample is recorded by two independent photolance detectors balanced by

Sensors are sensitive to the wavelengths of 425 and 450 ffi. The Pneata amplitude of both output signals., s - .. ,, ;, the common signals of photodetectors are multiplied using analogue

5 multiplier. The electrical signal obtained at the output of the analog multiplier is identified with an octane rating of 93 on the indicator scale. The same procedure is performed with another reference benzene, for example, grade A-76. The known rules for calculating the octane number of gasoline mixtures are used to plot octane number indicators in the range from 76 to 93.

5The method of identifying gasoline makes it possible to quickly and accurately estimate the octane number of gasolines and gasoline mixtures using available technical means. The method is suitable for any conditions, including road ones, as well as for assessing the quality of gasoline under conditions of a motor depot, when servicing cars.

Claims (1)

Claims of gasoline identification method, which includes the excitation and recording of gasoline fluorescence, the conversion of fluorescence intensity into electrical signals, according to which they are identified, differing 0 so that, in order to simplify the means of implementing the method and increase the accuracy and reliability of determining the octane number of gasoline, gasoline fluorescence is excited by radiation with a wavelength of 420 nm, fluorescence intensities are recorded at 425 and 450 nm and the product of amplitudes of electrical signals corresponding to both intensities - but m, judged on the octane number of gasoline.