JB/T 7984.2-1999 JB/T 7984.2-1999 Determination of bulk density of coarse abrasive grains of common abrasives JB/T7984.2-1999 Standard download decompression password: www.bzxz.net

JB/T7984.2-1999
This standard is equivalent to the revision of the international standard 1S0913611989 (the method for determining the bulk density of 95% common granular materials is required, and the bulk density determination is 3. This standard is a revision of JB/T7984.2-1999. The biggest difference between this standard and the original standard is that the measurement area has doubled. In addition, the measurement instrument and the measurement area calibration method are also different from the original standard. The technical content of this standard is equivalent to the international standard. , but the scraping operation is more specific than the provisions of the international standard. This standard replaces JB/T7984.2-95 from the date of implementation. This standard is proposed and submitted by the National Standardization Academic Committee for Scraping Materials. The drafting unit of this standard is Zhengzhou Precision Grinding and Grinding Research Institute. The main authors of this standard are Bao Hua and Li Changshi. This standard was first issued as GB3609-83 in 1983 and was adjusted to JB/7984.2-95 in April 1996. 179
JB/T 7984. 2-1999
ISO Foreword
ISO (International Organization for Standardization) is a world-wide joint organization composed of national standards bodies (ISO members). The formulation of international standards is usually carried out through ISO technical committees. Each member body interested in a certain profession has the right to participate in the technical committee of that profession. Governments or non-governmental international organizations related to ISO also participate in its work. IS has close links with the International Electrotechnical Commission (IEC) in all areas of electrotechnical standardization. Standards adopted by technical committees are voted on by the member bodies. The standard can only be published as an international standard if at least 75% of the member bodies voting on each technical committee agree. bZxz.net
International Standard ISO 9136 was prepared by Technical Committee ISO/TC 29 - Technical Committee for Tools. 180
Mechanical Industry Standard of the People's Republic of China
Conventional abrasive
Determinatien of bulk density of macrogrits1Scope
This standard specifies the method for determining the bulk density of conventional raw materials. This standard applies to back-through abrasives used for the manufacture of bonded abrasives and coated abrasives. Cited Standards
JB/T 7984.2,1999
eqv is0 9136: 1989
Replaces JB/T 7981.295
The following standards contain provisions that are incorporated in this standard or are provisions of this standard. When this standard is published, the versions adopted are valid. All standards are encouraged to be revised. Parties using this standard should explore the possibility of using the following standard revisions. GB/T4676-1984 Methods for extracting common materials GB/T 16458.1—1996
Scientific Terminology
3 Definitions
Part 1: Terminology of Materials
This standard uses the definitions in GB/T16458.1—1996. 4 Instrument
The hard density tester is shown in Figure 1. It includes the following parts: 4.1
It can keep the funnel in a vertical position and make the bottom of the funnel 76mm ± 1mm ​​above the top of the measuring tube. Cat funnel
The slope of the funnel is smooth enough so that the micro-tip will not stay on the slope. The funnel is made of stainless steel with smooth surface and its dimensional parameters are as follows:
Funnel height
Diameter of the funnel
Inner diameter of the cylindrical outlet
20 mm±0.5 mm
Height of the cylindrical outlet area
40mm±1mm
Drain valve with bucket
Can ensure the leak outlet is flat and closes freely. The induced drain valve shown in Figure 1 can be used. 4.4 Measurement system
The volume of the measuring cylinder is about 200m3. Its inner diameter is 64mm and the net height is 62mm. The inside of the measuring cylinder should be smooth. The accurate measurement of its volume should comply with the provisions of Chapter 5.
Zhoujia Machinery Industry Bureau 1999·10-0B approved 2000-03-01 real chain
4 branches
commercial Pili section loading ticket
4.5 sugar tray
JB/T 7984. 2 -1999
420±o. 5
outlet each
Figure 1 relative ticket whole volume density measuring instrument
measurement unit is placed in the overflow tray, the differential tray is used to collect the excess sugar material. 5 calibration of the measuring unit volume
before using the measuring unit, measure its volume according to the following method. Weigh the total weight of the micrometer of the dry bomb and a piece of flat glass (plate) (accurate to 0.01 g) Dimension unit: mm
Select the best (day state)
Fill the measuring tube with distilled water; the scraper is close to the front part of the measuring tube, and the water in the front part of the measuring tube is carefully scraped off. When the scraper scrapes off the excess water, weigh its total weight (accurate to 0.01 g). Calculate the volume of the measuring tube according to formula (1),
Where: V---type measuring tube volume.cm,
m. -. The mass of water in the first phase of the measurement + g;
rgu----the density of water at a certain temperature.g/cm182
Determination method
Sample preparation
JB/T7964.21999
The extraction and reduction of the sample shall be carried out in accordance with GB/T4676. The sample to be tested should be dried. The drying method is: place the sample to be tested in an oven, dry it at 110C for 1h, cool it to room temperature, and then perform determination.
6.2 Determination steps
Fill a 250ml beaker with the sample to be tested, close the discharge port of the funnel, and place the measuring cylinder at the center of its outlet. Pour the sample in the beaker into the funnel, open the discharge valve of the end funnel to let the sample fall freely until all the sample flows out. Vibration should be avoided during this process. Use a ruler to scrape off the excess abrasive on the measuring cylinder. When scraping, the ruler and the upper surface of the measuring cylinder are at an angle of about 45* (see Figure 2), and scrape four times perpendicular to each other. During this process, the abrasive in the measuring cylinder should be prevented from being compacted and finger movement should be avoided. Then weigh the mass of the abrasive in the measuring arm to an accuracy of 0.1g. The material is a material scale. Figure 2 shows the scraping operation. Measurement results. 7.1 Calculation method. Calculate the bulk density according to formula (2): Where: Bulk density. g/cm2: m---mass of dense material in the measurement tube + g---volume of the measurement tube. cm2. 7.2 Measurement results. A sample should be measured three times, and the arithmetic mean of the three results is taken as the measurement result. The error of the results of repeated measurements by the same operator using the same instrument shall not exceed ±0.02 g/cm2. (2)
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