This standard specifies the method for evaluating the hardness of petroleum wax by measuring the penetration depth of a standard needle. This standard is applicable to petroleum wax with a penetration value not exceeding 250. GB/T 4985-1998 Method for determining the penetration of petroleum wax GB/T4985-1998 Standard download decompression password: www.bzxz.net

GB/T4985—1998
This standard adopts the ASTM D1321-95 petroleum wax needle density determination method, and has revised GB/T 4985--B5t petroleum wax needle density determination method.
This revision mainly focuses on the sugar density and determination temperature of the method, and improves the determination means of the quotient point. Appendix A of this standard is the appendix of the standard
This standard replaces GB/T4985—1998 from the date of implementation. This standard is proposed by China Petrochemical Corporation. This standard is under the jurisdiction of Fushun Yanyou Chemical Research Institute. The drafting units of this standard are Fushun Petrochemical Corporation Oil Plant and Fushun Petrochemical Research Institute. The main drafters of this standard are Yang Hongmiao, Gao Suqing and Yang Lingju. This standard was first issued in March 1985. 1 Scope
National Standard of the People's Republic of China
Determination of needle
penetration of petroleum waxes This standard specifies the method for evaluating the hardness of petroleum waxes by measuring the penetration depth of a standard needle. This standard is applicable to petroleum waxes with a penetration value of not more than 250. 2 Reference standards
GB/T4985-1998
Replaces GB/T198585
The following standards contain provisions that become part of this standard through minor references. Unless otherwise specified in the standard, the following reference standards shall be the current valid standards.
SH/T0132 Determination of freezing point of petroleum wax
3 Terminology
Needle penetration of petroleum
The depth of a standard needle vertically penetrating a wax sample under specified conditions. 10! mm is from 4 Method Summary
The sample is melted, heated to about 17℃ above its freezing point, poured into a molding machine, cooled in air under controlled conditions, and then the sample temperature is controlled at the test temperature with a water bath. The penetration depth is measured with a penetrometer. The standard needle of the penetrometer is inserted into the sample 55 under a load of 100 g.
5 Significance and Use
The hardness of petroleum wax varies. Penetrometer is a method for measuring the hardness of petroleum wax. Hardness has a significant effect on other physical properties. 6 Instruments
6. 1 Penetrometer
It is used to make the standard needle contact the surface of the sample and give the penetration depth after the test. When the indicator reading of the needle meter is "equal", the needle tip should be able to accurately stand on the horizontal plane of the sample. The device in Figure 1 is a combination diagram of two adjustment methods: one is to adjust the test bench; the other is to adjust the indicator needle assembly. Either of the two can be selected. When released, the loaded needle must fall off without obvious resistance. The instrument is equipped with a horizontal adjustment screw and an alcohol level to ensure that the slide shaft is in a vertical position. The scale of the indicator is calibrated with an accuracy of 10/mm, and the scale range is not less than 250 10mm. Approved by the State Administration of Quality and Technical Supervision on June 17, 1998, implemented on December 1, 1998
6.2 Timer
GB/T 4985—1998
Figure 1 Needle meter
The needle meter can be equipped with an automatic release timing mechanism, or it can be used with a scale of 0.1 6.3 Standard needle and slide bar
The size requirements of the standard needle are shown in Figure 2. The needle is about 83 mm long and one side of the needle is symmetrically processed into a solid cone. The cone angle of the cone is in the range of 855'~9°25. The body axis coincides with the needle bar axis, and the maximum heart rate (indicator full-scale scale) is within 0.13mm. The body part should be made of fully hardened and tempered 440-C grade or equivalent stainless steel with a Rockwell fineness of C57~60. The tip is polished and the tail is cut off to form a truncated circular body. The cross-sectional diameter of the small head is 0.14~0.16mm. The cross section is at right angles to the needle axis, and the allowable deviation is within 2°. The edge should be sharp and without thorns. The roughness of the cone surface and the cross section is 0.2 μm. The actual weight of the standard needle is 2.5 g±0.05 g (adjusted by the rod drilling depth), the total weight of the clean rod is 47.5g ± 0.05g·50g ± 0.05g weight is added to the sliding rod. Note: The standard needle must be calibrated by the metrology department according to the requirements of the ball, 8*65\g*25
p3.84~4.28mm
-58mml
Figure 2 Standard needle
6.4 Sample former
0. 14~0. 16mm
The former is a yellow steel ring cylinder with open ends, with an inner diameter of 25.4mm, a height of 31.8mm, and a wall thickness of 3.2mm. In order to prevent the hard end sample from sliding, a few burst-like grooves are engraved on the center of the inner wall of the cylinder. When the sample is formed, measure the former on a brass plate moistened with an equal volume of glycerin and water mixture.
6.5 The laboratory or test book
can maintain 23. 9℃±2.2℃.
6.6 Water bath
The volume of the water bath is not less than 10 L, and it can maintain the test temperature accurately to ±0.1 C. The water bath can be made of glass or have a viewing window for horizontal observation of the GB/T 4985-1998
sample. The depth of the sample immersed in the water bath is not less than 102 mm, and it is placed on a multi-support adjustment rack not less than 51 mm from the bottom of the bath. A fixed porous sample rack is also required to be installed about 51 mm below the water surface to support the sample for needle penetration measurement. The measurement can also be carried out in another small constant temperature water bath, see Appendix A for details. 6.7 Thermometer
The thermometer is a precision thermometer used for water temperature measurement, full immersion type, with a scale range of 25~～55 C. Specific requirements are as follows: Temperature range
Minimum division
Long line division
Scale division
Indication error
Allowable maximum heating temperature
Rod diameter
Mercury ball length
Mercury ball diameter
Freezing point range
Distance from ball bottom to freezing point
Distance from ball bottom to contraction chamber bottom
Distance from ball bottom to contraction chamber
Distance from ball bottom to 25°C scale line
Distance from ball bottom to 55°C scale line
6.8 brass plate
25~55°C
Maximum 0.1°C
105°C
379 mm±5 mmbZxz.net
7~8 mm
25~35mm
-0. 5~+0. 5℃
6070 mm
Minimum 80 mm
Maximum 100 mml
115~135 mm
324~~344 mm
The specification of the yellow steel plate is 63.5mm×3Bmm×6. 4mm, which is used to support the sample during molding. The plate should be heavier than the soft plug during the sample cooling period.
7 Sample preparation
Heat the wax sample to about 17℃ above its freezing point to prevent local overheating. Stir well to make the wax sample homogeneous and avoid bubbles. In a test room or test box maintained at 23.9℃±2.2℃, place the yellow steel plate on two soft plugs (No. 16 and No. 18), and then wet the upper surface of the brass plate with an equal volume of glycerol and water mixture. Place the former on the brass plate and pour the wax sample into the former so that it forms a convex meniscus. Cool it at 23.9°C ± 2.2°C for 1 h. Then scrape the convex wax from the top of the former and remove it on the brass plate. Place the wax surface in contact with the brass plate in a water bath at the test temperature ± 0.1°C for 1 h. Note: Very hard fins tend to shrink and separate from the former. In this case, it is allowed to inject more wax sample to make it close. 8 Test steps
8.1 Turn the base of the needle meter to the back, so that the head of the needle meter is at the edge of the water bath, and place it above the porous test frame supporting the specimen. It may be necessary to place a weight on the base to balance the weight of the head. Adjust the needle meter and the porous test frame in the water bath to a horizontal level. Alternatively, the small water bath can be placed on the thermometer stand, and the water temperature in the small water bath is maintained within the test range of ±0.1°C (see Appendix A). Before each measurement, the temperature of the small water bath is measured with the thermometer specified in 6.7. When the correction value of the exposed part of the thermometer is equal to or exceeds 0.05°C, the correction value needs to be added. 8.2 Place the former with the sample on the porous test frame or in the small water bath, so that the smooth surface in contact with the brass plate is on the surface, and ensure that the former and the test frame or small water bath are not visible during the test. The water level is adjusted to 25mm above the upper surface of the sample, and the sample is kept within the test range of ±α.1.
Note: The test temperature can be a temperature within the range of 25 to 55°C, and 25°C, 35°C, 45°C or 50°C are usually used. 8.3 Add 50 g of the substance to the standard needle, so that the total mass of the needle and its accessories is 100 g ± 0.15 g. Check whether the release mechanism is stuck. The indicator should be at the "zero" position. Adjust the indicator assembly or adjustment table according to the different types of needle penetration meter, adjust it until the needle tip almost touches the wax surface, and fix the position.
8.4 Use the withdrawal method to make the needle tip just touch the wax surface of the sample. Observing the projection of the needle tip will help to accurately adjust. After 5 minutes, release the slide bar and keep it for 5%. Use an automatic timer or a 0.1-division stopwatch to time. Use a stopwatch to start the stopwatch before the test. When the second hand of the stopwatch reaches a certain scale, release the slide bar. When it reaches 5 seconds, immediately lock the slide bar. Gently press the indicator bar until it is supported by the slide bar, and read the needle penetration value from the indicator dial.
8.5 On a circumference at least 3.2 mm from the edge of the former, take four points of approximately equal spacing (not less than 12.7 mm) for measurement. Before measuring each point, wipe the needle tip carefully with a clean dry cloth to remove all attached wax, and position the standard needle according to the requirements of 8.4 before measuring.
9 Report
Take the arithmetic mean of the measured values ​​at the four points as the measurement result, accurate to 10-[mm, and report the test temperature at the same time. 10 Precision and Bias
10.1 The precision of the method is determined by statistical analysis of the results of full determinations between laboratories as follows: 10.1.1 Repeatability
The difference between the results of two consecutive measurements of the same sample made by the same operator under constant operating conditions exceeds the value calculated by the following formula only once in twenty times. r = 1.72 × [10:0 4(3
Where: -
- Repeatability:
is the degree of penetration.
10.1.2 Reproducibility
The difference between any two independent results obtained by different operators in different laboratories on the same sample exceeds the calculated value below only once in twenty.
Where: R -
Reproducibility:
X --- Degree of penetration
R = 4.81 × [100.00 2(3
（2）
10.1.3 The repeatability and reproducibility of each penetration value calculated by the above two formulas are listed in Table 1. Table 1 Repeatability and reproducibility calculated for different penetration values ​​Penetration
10.2 Deviation
Repeatability
Reproducibility
Needle penetration Meaning
Because the determination of the penetration value is based on only one test method, this method has no deviation. Repeatability
Reproducibility
GB/T4985-1998
Appendix A
(Appendix to the standard)
Small water bath thermostat
A1 This device is specially developed for paraffin wax needles. It can perform computer intelligent control on four constant temperature points. Press the required temperature button to enter the automatic control of heating and constant temperature state.
2 During the heating stage, due to different environmental influences, it can exceed the constant temperature point 1 or so. At this time, it can be automatically returned to the constant temperature point without using other cooling methods.
3 The ambient temperature should be between 15 and 25℃, and the indoor air should be stable. A3
The constant temperature accuracy is 10.1℃, and it must be evenly balanced up and down and left and right: 5 The small water bath matched with the thermostat has an outer diameter of 140 mm ± 1mm ​​and a height of 80mm ± 【mm. The bottom inside and outside must be as flat as the glass plate A5
to prevent the molding device and the small water bath from moving.
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.