Coning degree is a quality index to measure the consistency of grease.It refers to the depth of vertical penetration of a standard cone (needle) into a solid or semi-solid petroleum product, expressed in units of 0.1mm, under specified conditions of mass, time and temperature.Coning degree meter is a measuring instrument specially used for measuring the coning degree of grease. It consists of reading indicator, cone, platform, centering device and horizontal adjusting screw and other components.Coning degree meter with a variety of special cone and adjust to a variety of different standard quality, can be respectively on the coning degree of all kinds of grease.

　　One, the technical requirements of the coning degree meter

　　According to the provisions of grease and petroleum grease coning degree determination method (GB/T269-91), the coning degree of grease is at 25℃, the cone assembly is released from the coning degree meter, so that the cone falls for 5 seconds, and determine the depth of its penetration into the sample.According to the different test conditions and samples, the coning method can be divided into three parts: full-size cone method of grease, 1/2 and 1/4 proportional cone method and full-size cone method of petroleum grease.There are two types of full-size cones: "standard" and "optional" for cones greater than 400 units, and "optional" for cones less than 400 units.The sample size is small and the full-size cone penetration is 175 ~ 385 units. 1/4 scale cone can be used.

　　Full size cone method of grease, 1/2 and 1/4 scale cone method and according to the different instruments and test conditions, divided into not working, working, prolonged work and block cone penetration and other four methods.

　　Non-working coning degree - the coning degree measured at 25℃ when the grease sample is transferred to the grease cup or container of the same size under the condition of as little agitation as possible.

　　Working coning degree - it is the technical standard of grease used most, it is the sample in grease operator, constant temperature 25℃ and give reciprocating work 60 times immediately after the coning degree.

　　Extended working coning degree - under specified conditions, the sample in the grease operator after more than 60 reciprocating work measured coning degree.

　　Block coning degree - the coning degree measured when the specimen is hard enough to retain its shape without a container.

　　The use of coning degree meter to determine the coning degree of grease, the main equipment required:

　　1.Coning meter.

　　2.Cone :(1) the total mass of the full-size cone is 102.5g±0.05g, and the mass of the cone rod is 47.5g±0.05g.(2) The mass of 1/2 cone was 37.5g±0.05g.(3) The mass of 1/4 scale cone was 9.38g±0.025g.

　　3.Grease operator: (1) Full-size grease operator: composed of handle, thermometer, sealing nut, exhaust valve, cover and other parts.The working speed should reach 60 times /min±10 times /min, and the working process is 67 ~ 71mm.(2) The working speed of the 1/2 proportion grease operator should reach 60 times /min±10 times /min, and the working process is 35mm.(3) The working speed of 1/4 proportion grease operator should reach 60 times /min±10 times /min, and the working process is 14mm.

　　4.Fat cup temperature: should be controlled at 25℃±0.5℃.

　　5.Oven: can maintain 85℃±2℃, used for melting petroleum grease sample.

　　6.Grease cutter.

　　7.Petroleum grease sample container: diameter 100±5mm, depth 65mm or greater, thickness of at least 1.6mm metal plate made of flat bottom circular container, and equipped with a lid.

　　Two, the factors affecting the accuracy of the coning degree of grease

　　1.The total mass of the cone.The standard test method (GB/T269-91) has requirements on the mass of the cone and rod, but the actual measurement only requires that the total mass of the two meet the requirements, and their respective mass is allowed to change in a wider range.If the total mass of cone and rod is artificially increased or decreased, it will be found that with the increase of total mass, the measured value of cone penetration will increase significantly.

　　2.Fat cup temperature.The thermometer shall be verified according to (JJG50-86) and shall be strictly controlled at 25±0.5℃ after being inserted into the fat cup.The test results show that the temperature of grease cup has obvious influence on the coning degree measurement results, and the coning degree value increases with the increase of temperature when the same grease sample is measured at different temperatures (23℃ ~ 27℃).

　　3.Sample temperature.When the difference between room temperature and the measured temperature is large, the constant temperature time should be appropriately extended to ensure that the sample temperature really reaches the measured temperature.During the determination of temperature, the sample shall not be added to the fat cup without constant temperature and agitation.Therefore, the excess sample after scraping can be stored at the determined temperature for later use.

　　4.Bubbles in the sample.There should be no air bubbles in the sample, because if there are air bubbles, the coning degree will be too large.

　　5.The position of a cone rod.The taper should be adjusted perpendicularly to allow free fall.The inner wall of the casing and the surface of the cone should be wiped clean with gasoline to avoid increasing friction between them.

　　6.Release time.The release time has a certain effect on the coning degree.The test results show that with the increase of the release time, the measured coning degree value also increases, too short or too long time will have a certain influence on the measured results.

　　7.The depth to which a cone sinks.After stopping the cone sinking into the sample, gently pull down the indicating rod, so that it is just the top of the cone rod, must not be too hard, otherwise the cone will continue to sink because of the impact, so that the result is large.

　　Three, the significance of measuring the coning degree of grease

　　1.Coning degree is an indicator of consistency or hardness of grease and petroleum grease.The greater the coning degree of the grease, the smaller the consistency, the softer the grease.On the contrary, the coning degree is small, the consistency is large, and the grease is hard.The grease grade (consistency grade) is based on the coning range.The smaller the number, the greater the coning degree value, the smaller the grease consistency.

　　2.Coning degree is one of the bases of how to choose grease correctly.Small coning grease, its consistency is large, can withstand greater pressure, but the mechanical movement of the resistance is also large, in addition to filling is more difficult;The coning degree of grease is large, its consistency is small, the resistance to mechanical movement is small, filling is easy, but the ability to bear pressure is poor.Therefore, in practice, in the friction parts with high pressure and slow speed, it is advisable to choose grease with small coning degree.And in the friction parts of small pressure and high speed, it is advisable to choose grease with large coning degree.Too large or too small coning can not give full play to its lubrication performance.Because the coning degree is a highly conditional test, the results of the determination are quite different from the actual work efficiency, leaving other analysis items, only relying on the coning degree of an index is not able to determine the use of grease.

　　3.Determination of coning degree can also indirectly see the content of grease thickener.The less the thickener content, the greater the coning degree.Conversely, the coning degree is smaller.