This standard specifies the method for determining the Saybolt color of petroleum products using a Saybolt colorimeter. This standard applies to refined petroleum products such as undyed motor gasoline, aviation gasoline, jet fuel, naphtha, kerosene, white oil and petroleum wax. GB/T 3555-1992 Determination of the Saybolt color of petroleum products (Saybolt colorimeter method) GB/T3555-1992 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of Saybolt color-Saybolt chromometer method for petroleum products
(Saybolt colorimeter method)
Petroleum products-Determination of Saybolt color-Saybolt chromometer method Subject content and scope of application
This standard specifies the method for determining the Saybolt color of petroleum products using a Saybolt colorimeter. GB/T 3555-92
Replaces GB3555-83
This standard applies to refined petroleum products such as undyed motor gasoline, aviation gasoline, jet fuel, naphtha, kerosene, white oil and petroleum wax. wwW.bzxz.Net
Note: Petroleum products darker than Saybolt color No. 16 can be determined using GB/T6540. 2 Reference standards
GB/T6540 Determination of color of petroleum products
SH/T0132 Determination of freezing point of petroleum wax
3 Terminology
Saybolt color: When the liquid column of the sample is observed and compared with the standard color plate, the liquid column height value that is closest to one of the three standard color plates is measured, and the Saybolt color number is found according to Table 1. The Saybolt color number is specified as -16 (darkest) to +30 (lightest). 4 Method summary
Adjust the liquid column height of the sample according to the specified method until the sample is obviously lighter than the color of the standard color plate. Regardless of whether the sample color is darker, suspicious or matched, the Saybolt color number corresponding to the previous liquid column height of the sample is reported. 5 Instrument
The Saybolt colorimeter consists of a sample tube, a standard color plate glass tube, a light source, a standard color plate and an optical system. See Appendix A and Figure Al for details.
6 Instrument calibration
6.1 Remove the glass disc from the bottom of the sample tube. Clean the sample tube, standard color plate glass tube and glass disc. If the sediment cannot be removed by rubbing and using solvents, wash it with soap and water, then rinse it with distilled water, acetone or other solvents and dry it. Assemble the clean sample tube, standard color plate glass tube and glass disc on the instrument. 6.2 Remove the 12mm inner diameter light bar at the bottom of the standard color plate glass tube, illuminate it with the specified light source and reflector, observe the light intensity of the optical field of view of the two empty tubes, and adjust the position of the light source to make the light intensity of the two divided fields of view the same. 6.3 Reinstall the 12mm light bar at the bottom of the standard color plate glass tube. Fill the sample tube with distilled water. At this time, the light intensity of the two optical divided fields of view must still be the same, so that the glass tube color can be considered to match and the instrument meets the use requirements. The optical properties of the glass tube are very important. The same material will vary depending on the batch number, so color-matched glass tubes must be used. When a glass tube is broken, a pair of glass tubes with matching colors should be replaced. 7 Sample preparation
When the sample is turbid, it can be filtered with multiple layers of qualitative filter paper until it becomes transparent. 8 Test steps
8.1 Test steps for refined light oil and white oil 8.1.1 First rinse the sample tube with part of the sample and make the sample in the tube flow out completely. No oil droplets are allowed to remain on the tube wall. Fill the sample tube with the sample. Inject the sample slowly. If bubbles are found in the sample, use a glass rod to expel them. 8.1.2 Use a full-thickness standard color plate to compare the color with the sample. If the color of the sample is lighter than the standard color plate, replace the half-thickness standard color plate with the full-thickness standard color plate for color comparison. If the color of the liquid column height of the sample at the scale of 6.25 is darker than that of one full-thickness standard color plate, replace it with two full-thickness standard color plates.
Table 1 Comparison table of Saybolt color number and liquid column height of sample Standard color plate
1 half-thickness plate
1 full-thickness plate
2 full-thickness plates
Liquid column height of sample
Saybolt color number
Standard color plate
2 full-thickness plates
Liquid column height of sample
Saybolt color number
8.1.3 After selecting the standard color plate, adjust the liquid column height of the sample so that the color of the sample is darker than the standard color plate. Discharge the sample according to the liquid column height of the sample in Table 1, and discharge it to the liquid column height of the sample that is closest to the selected standard color plate in Table 1. If the sample is still darker, discharge it to the next liquid column height of the sample specified in Table 1 for color comparison, and repeat this operation until the color of the sample is closest to or slightly different from the standard color plate. After confirming this, discharge the sample to the next liquid column height of the sample specified in Table 1. When the color of the sample is undoubtedly lighter than the standard color plate, record the Saybolt color number corresponding to the previous liquid column height of the sample. 348
GB/T3555---92
Note: According to the experience of using this instrument, it is not necessary to select the standard color plate step by step according to the operating steps of 8.1.3. The measurement steps are shown in Table 2. Table 2 Operation Example
When the liquid column height of the sample reaches the value on the right, the color is darker than the standard color plate When the liquid column height of the sample reaches the value on the right, the color is darker than the standard color plate When the liquid column height of the sample reaches the value on the right, the color is difficult to judge When the liquid column height of the sample reaches the value on the right, the color is lighter than the standard color plate Saybolt Color Number
8.2 Test steps for petroleum wax
One full-thick standard color plate
8.2:1 Heat the petroleum wax sample to 8~17℃ above its freezing point (determination method according to SH/T0132), two full-thick standard color plates
8.2.2 Preheat the sample tube, inject the melted petroleum wax sample into the sample tube, and turn off the heater. When the wax sample heat wave in the sample tube disappears, proceed according to the steps specified in Article 8.1.
9 Precision
Judge the reliability of the test results (95% confidence level) according to the following provisions. 9.1 Repeatability: The difference between two results measured repeatedly by the same operator shall not be greater than one Saybolt color number. 9.2 Reproducibility: The difference between two results reported by different laboratories shall not be greater than two Saybolt color numbers. 10 Report
The color number recorded in the report shall be marked with "Saybolt color number ××". If the sample is filtered, the words "sample filtered" shall be written. 349
A1 Saybolt colorimeter
A1.1 Sample tube
GB/T3555-92
Appendix A
(Supplement)
Use borosilicate glass tube or glass tube with equivalent color characteristics, with an inner diameter of 16.5~～17.5mm and an outer diameter of 21.25~～22.75mm. Use a 6.25mm thick optically transparent flat glass disc without scratches and lines to seal the bottom of the tube. The length from the upper surface of the disc at the bottom of the tube to the top of the tube is 508 to 510 mm. The tube and disc are installed on a metal sleeve equipped with a metal drain valve, as shown in Figure A1. The metal sleeve structure should be easy to disassemble and easy to clean the glass disc. The tube is graduated according to 1/8 inch (3.2 mm), with a circle engraved every lin (25.4 mm), and the number is engraved upward from the 2 inch (50.8 mm) line.
Note: Pyrex glass is suitable, and glass of equivalent quality can also be used. Domestic GG17 glass is equivalent to it. A1.2 Sample tube heater
Figure A1 Saybolt colorimeter and artificial fluorescent lamp are used to test petroleum wax. The specifications of the sample tube described in A1.1 should be met, and a 60W heating wire is evenly distributed throughout the sample tube, as shown in Figure A2. This heater should keep the wax sample in a liquid state and facilitate reading. A1.3 Standard color plate glass tube
The material, color and inner and outer diameter are the same as those of the sample tube, 483mm long, open at both ends, and fixed on the metal sleeve at the lower end. A removable black metal light bar with an aperture of 12mm and a rotating disk for placing the standard color plate are installed in the optical path of the metal sleeve. The total length of the assembled standard color plate glass tube is 516~~518mm.
A1.4 Color requirements for glass tubes
When the sample tube and the standard color plate glass tube are both empty or the sample tube is filled with distilled water, there should be no color difference between the two. Compare on the instrument according to the relevant contents described in Chapter 6 of this standard. A1.5 Tube assembly
The sample tube and the standard color plate glass tube should be fixed vertically in the center of the optical eyepiece, and covered with a removable diaphragm metal cap of about 25mm long on the upper end of the tube. The diameter of the cap should be convenient for it to slide on the end of the tube, and the diameter of the small hole on the diaphragm of the metal cap is 14mm. 350
GB/T3555--92
Note: The handle is fixed at the locking ring.
Figure A2 Saybolt colorimeter sample tube heater 14
1--Sample = 2-· Spring: 3 Small cock: 4--Tight ring; 5--Glass disc; 6--Gasket; 7-Axis; 8-Tube seat; 9-Ring shell, 10 Ring; 11 Sealing glue, 12-Locking ring; 13--~60W heating wire, 14--Tube cover, 15 Oil drain port A1.6 Optical observation instrument
A1.6.1 The optical observation instrument consists of a prism and an eyepiece lens. The refraction angle of the prism matches the refraction zone to avoid misalignment after installation. Adjust the prism so that the light passing through the tube is refracted into the photometer head and a circular field of view can be observed through the eyepiece. Half of the field of view is illuminated by the light passing through the sample, and the other half is illuminated by the light passing through the standard color plate. The circular field of view should be free of distortion and parallax. A1.6.2 The light can be directed through the center of the eyepiece by using an adapter (Figure A3). The adapter is composed of a metal sleeve with a diameter that fits the outer diameter of the eyepiece and is about 50 mm long. One end of the adapter is closed with a metal diaphragm with a central aperture of about 2.5 mm. 351
A1.7 Illumination
GB/T3555-92
Figure A3 Adapter
Use a reflector made of milky white glass or transparent glass with a surface evenly coated with glossy silver, and fix it at a suitable angle so that the reflected light of equal intensity passes through the two tubes as parallel rays. The scattered light can also be directly injected into the tube from the bottom of the instrument. A1.8 Light source
Use artificial daylight as the light source to inject the scattered light into the tube. The scattered light should be free of glare or shadow, and all other external light interference should be eliminated. A2 Standard color plate
The standard color plate is a round glass plate. There are two types: full thickness and half thickness. When the chromaticity characteristics are calculated using the spectral transmittance of the 1931 International Commission on Illumination (ICI) standard illuminant C, the light transmittance r and chromaticity coordinates X, Y, and Z should meet the following requirements: Chromaticity characteristics
Full thickness standard color plate
0.860~0. 865
0.342~0.350
0.367~0.378
0. 272~0. 291
Half thickness standard color plate
0. 888~-0. 891
0. 327~0. 331
0.344~0.350
0. 319~~0. 330
The standard color plate is placed on the turntable at the bottom of the standard color plate glass tube. A3 fluorescent lamp
Uses milky white civilian lighting bulbs with a rated power of 60W. The inner surface is polished, and the color temperature is about 2750K, and the light efficiency is about 13lm/W. The bulb is fixed on a standard socket equipped with a hemispherical reflector. As shown in Figure A1. A3. 2 Reflection
It is hemispherical, and the inner surface is unpolished with extremely fine aluminum bronze powder, and then evenly sprayed on the surface with heat-resistant bronze liquid. This polishing coating should achieve non-selective absorption, and its initial reflectivity is above 65%. A3.3 Daylight filter
A3.3.1 The daylight filter is a convex-concave glass sheet. The concave surface must be sandblasted and pickled for surface hardening, and it must fit tightly with the opening of the hemispherical reflector to achieve dustproof on the inner surface. When the chromaticity characteristics of daylight filters are calculated using the spectral transmittance of the 1931 International Commission on Illumination (ICI) standard illuminant A, the light transmittance and chromaticity coordinates X, Y, and Z should meet the following requirements: 352
Chromaticity characteristics
GB/T3555—92
0. 107~~0. 160
0. 314~0. 330
0. 3370. 341
0. 329~0. 349
A3.3.2 When inspecting daylight filters by spectrophotometry, a qualified daylight filter should have a transmittance higher than 60% at a wavelength of 410nm and a transmittance lower than 10% at a wavelength of 700nm. The transmittance curve in this area is a smooth curve and should not have the characteristic absorption peak of diamond. The transmittance of the typical absorption curve of diamond at a wavelength of 570nm is higher than the connecting line of the transmittances of 540nm and 590nm, and it also shows a red light absorption band with high transmittance in the wavelength region of 600nm and greater. The transmittance of a qualified daylight filter at a wavelength of 570nm is no more than 3% higher than the straight line connecting the transmittances of 540nm and 590nm, and the transmittance at a wavelength of 700nm cannot exceed 3% at any short wavelength such as 600nm. Additional remarks:
This standard was proposed by China Petrochemical Corporation. This standard is under the technical jurisdiction of the Petrochemical Research Institute. This standard was drafted by Fushun Petrochemical Research Institute. The main drafters of this standard were Lai Yuzhen and Yang Ling. This standard is equivalent to the American Society for Testing and Materials standard ASTMD156-87 "Standard Test Method for Saybolt Color of Petroleum Products (Saybolt Colorimeter Method)".
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