This standard specifies the determination method of acetylene black resistivity. This standard is applicable to the determination of acetylene black resistivity. ? GB/T 3781.9-1993 Determination of acetylene black resistivity GB/T3781.9-1993 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Acetylene black-Determination of resistivity
Subject content and scope of application
This standard specifies the method for determining the resistivity of acetylene black. This standard applies to the determination of the resistivity of acetylene black. 2 Reference standards
Determination of carbon heating loss
GB/T 3780.8
3 Principle
CB/T 3781. 9-93
Replace GB3781.9-83
Put the sample in basic insulating dibutyl phthalate, and use an electric stirrer to disperse and evenly mix it to form a stable suspension. Determine the resistivity of the suspension to characterize the strength of the conductivity. 4A method (arbitration method)
4.1 Reagents
4.1.1 Dibutyl phthalate; analytical grade. 4.1.2 95% ethanol (GB679), analytical grade. 4.2 Instruments
4.2.1 Ethyl fast carbon black resistivity tester: domestic TBY-30 model meets the requirements of this standard. 4.2.2 Constant temperature drying oven: can be controlled at 105±2℃. 4.2.3 Dryer.
4. 2. 4 Analytical balance; accurate to 0. 1 mg. 4. 2.5 Measuring cylinder: 50 mL, accuracy is 1 mL. 4.2.6 Beaker 150 mL
4.2.7 Determination cell: as shown in Figure 1.
Approved by the State Administration of Technical Supervision on March 3, 1993, and implemented on December 1, 1993
4.3 Procedures
CB/T 3781. 9—93
42× 42
36×36 + 0.1
Figure 1 Specifications of measuring cell
1--Resistance measuring cell+2 Silver sheet electrodes. Area 1.79.cm3: 3 Electrode silver wire lead: 4-Lead wire sleeve
4.3.1 Take an appropriate amount of sample and put it into a beaker. According to the provisions of GB/T 3780.8, place it in a constant temperature drying oven at 105±2℃ and dry it for 1 hour. Move it into a desiccator to cool it for use.
4.3.2 Weigh the dried sample area 1, accurate to 0.5mg. 4.3.3 Slowly add 50 mL of diisophthalic acid to a clean and dry 150 mL beaker (4.2.6). 4.3.4 Turn on the power of the TBY-30 acetylene black resistivity tester (4.2.1) and preheat for 30 minutes. 4.3.5 After the sample is completely soaked, put it into the stirrer adjusted in advance according to the instrument manual, and put its stirring paddle into the center of the beaker (4.2.6), 13.5 mm from the bottom.
4.3.6 Adjust the speed to 1 050~1 100 r/min, set the timer to 10 minutes, and stir immediately for 10 minutes. 4.3.7 Determination of resistivity
4.3.7.1 Place the dry and clean resistivity test cell (4.2.7) in the test clip and turn on the measurement switch. 4.3.7.2 Pour all the suspension in the beaker into the measuring cell and let it stand for 1 min. Press the read key and the number displayed on the display is the resistivity.
4.4 Result indication
The resistivity of the sample is read directly on the display, and the result is accurate to 0.1α·m. 4.5 Permissible difference
The difference between two test results shall not exceed 0.4 n·m. 4.6 Test report
The test report shall include the following items:
The national standard number based on which this test is conducted;
The type and mark of the sample;
The average value of the two test results;
Indicate the differences from the prescribed test steps; Test date.
5.1 Reagents
5.1.1 Butyl phthalate: analytical grade, 5.1.2 95% phthalic acid (GB 679): analytical grade. 5.2 Instruments
5.2.1 Ohmmeter.
GB/T 37B1. 9 93
5.2.2 Electric stirrer (including micro motor and stirring paddle). 5.2.3 Micro motor. Model U25/20-220, 25W, 220V, 0.37A, 60C, 50Hz, 4000r/min continuous, 5.2.4 Stirring paddle: homemade, welded at right angles in transverse and weft directions, diameter 3.0~3.2mm, length 40mm. Made of stainless steel. Specifications as shown in Figure 2.
Figure 2 Specifications of stirring paddle
Figure 3 Schematic diagram of connection between stirring device and speed measuring device 1 Power supply: 2 Voltage stabilizer; 3-coupled transformer: 4--micro motor + 5--coupling 6 Reflective tape; 7 Photoelectric tachometer; 8-stirring cylinder; 9-beaker 5.2.5 Photoelectric tachometer: The domestic tachometer with model SZG.1 meets the requirements of this standard. 5.2.6 Coupling transformer.
5.2.7 Voltage stabilizer.
5.2.8 The stirring device and the measuring device are connected as shown in Figure 3. 5.2.9 Determination cell; as shown in Figure 1.
5.2.10 Constant temperature drying oven: can be controlled at 105±2℃. Desiccator.
Analytical balance: accurate to 0.1mg
5.2.13 Stopwatch.
5.2.14 jar: 50mL, precision is 1ml.
Beaker: 150mL.
5.3 Procedures
5.3.1 Take an appropriate amount of sample and put it in a beaker. According to the provisions of GB, place it in a constant temperature drying oven at 105±2°C for 1h, transfer it to a desiccator and cool it for later use.
5.3.2 Weigh 1g of the dried sample above, accurate to 0.0005g. 5.3.3 Place the sample (5.3.2) in a clean and dried 150mL beaker (5.2.15), and slowly Add 50 mL of o-phthalic acid ester (5.1.1)
5.3.4 Turn on the power supply, adjust the speed of the stirrer to 1450~1500r/min using the adjustable autotransformer (5.2.6), and then cut off the power supply CB/T3781.9-93
5.3.5 After the sample is completely moistened, place it in the stirring device that has been connected in advance according to Figure 3, so that the distance between the stirring paddle and the outer bottom of the beaker is 13.5 mm (as shown in Figure 4).
Figure 4 Distance between stirring paddle and outer bottom of beaker
1 Stirring paddle: 2-Beaker
5.3.6 Turn on the power supply, and the motor speed will be reduced to 1050~1100r/min by the resistance of the mixture in the beaker. Note: If the speed is not constant at 1050~1100 1/min during the stirring process, immediately adjust it with the transformer. 5.3.7 Immediately use a stopwatch to accurately record the stirring time. After 10 minutes, stop stirring, remove the beaker, and measure immediately. 5.3.8 Determination of resistivity
5.3.8.1 Before measuring, connect the measuring device according to Figure 5. 6
Figure 5 Schematic diagram of measuring device connection
【One thousand battery; 2-ohmmeter positive pole ② negative pole 1 ohm terminal @-ground terminal! ?-Select the resistance range, start with a level adjustment 3-resistance measuring cell 5.3.8.2 Turn on the power, preheat for 10min, adjust the meter pointer so that it is zero when short-circuited and α when disconnected. 5.3.8.3 Connect the two electrodes of the dry and clean resistivity measuring cell to the circuit, check whether the meter pointer points to %, otherwise the resistivity measuring cell should be further cleaned. After meeting the requirements, adjust the range to RX100 for standby use. 5.3.8.4 Pour all the mixture in the beaker into the prepared resistivity measuring cell, wait for the pouring to be completed, let it stand for 1min and then read the value, accurate to 20.
5.4 Result expression
The resistivity R of the sample is calculated as follows:
In the formula, r
Measured resistance of the sensing liquid, kn
A——Electrode area of ​​the measuring cell, 1.79cm
GB/T 3781.9-93
SDistance between the two electrodes of the measuring cell, 3.6 cm. www.bzxz.net
The calculation result is accurate to 0.10·m.
5.5 Allowable difference
The difference between the two measurement results shall not exceed 0.4.0+m. 5.6 Test report
The test report shall include the following items:
National standard number on which the test is based;
Type and mark of the specimen;
Average value of the two test results;
Indicate the differences from the prescribed test steps; Test date.
Additional remarks:
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Carbon Black Industry Research and Design Institute of the Ministry of Chemical Industry. This standard was drafted by the Carbon Black Industry Research and Design Institute of the Ministry of Chemical Industry. The main drafters of this standard are Yu Lian and Meng Chuanying.
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