Test method for temperature (Tk-100) of electronic glass with volume resistivity of 100MΩ.cm
Some standard content:
National Standard of the People's Republic of China
Test method for temperature (T-..)while volume resistibity of
electronic glass is 100MQ·cmThis standard applies to the test of temperature (Tr-100) while volume resistibity ofwwW.bzxz.Net
electronic glass is 100MQ·cm. 1 Method Summary
GB9622.8—88
Reduced to SJ/T11042-96
Glass has the property of ion conductivity. When a DC voltage is applied to the sample, a small current passes through the sample and conducts electricity. The resistance and volume resistivity of the sample can be calculated according to Ohm's law. When the temperature is below the transition temperature, the volume resistivity decreases as the temperature increases, and their relationship conforms to formula (1):
Where: p is the volume resistivity of glass, a·cm, T is the thermodynamic temperature, K,
A, B are constants.
(1)
The corresponding volume resistivity at different temperatures is determined, and the temperature when 1gp=8, that is, Tx-100, can be obtained by formula (1) or by drawing a graph. 2 Test equipment and materials
The test equipment is shown in Figure 1, and the test circuit is shown in Figure 2. 2.1 Vertical electric furnace.
2.2 DC regulated power supply, stability 0.5%. 2.3 DC voltmeter, measurement range 0~500V, accuracy 0.5 level. 2.4 Galvanometer, sensitivity not less than 10-A/mm, accuracy 0.5 level. 2.5 Thermometer, 0~500℃.
2.6 Low temperature silver paste.
Approved by the Ministry of Electronics Industry of the People's Republic of China on March 21, 19881
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Implemented on February 1, 1989
GB9622.8-88
Figure 1 Test device
1 Base 2 Insulating base 3- Round head screw, 4- Lug; 5 Pin, 6- Support sleeve, 7- Small spring: 8- Quartz tube, 9 Movable electrode, 10 Measuring base: 11- Glass sample, 12- Small quartz tube: 13- Heat dissipation cover (or measuring head), 14- Terminal 15 Mercury thermometer: 16-fastening nut, 17-blocking diagram, 18-heating furnace 19-straight screw; 20-mica gasket 21-support rod: 22 conversion switch, 23-terminal: 24-support foot; 25-pad diagram: 26-hexagonal nut-220V
Figure 2 Test circuit
1-rectifier: 2-voltage regulator, 3-voltmeter: 4-galvanometer, 5-measurement instrument 3 Sample preparation
3.1 Select a glass rod without defects such as stones, bubbles and stripes, with a diameter of 8.5±0.5mm and a length of 11±0.5mm. A set of 2 samples.
3.2 Finely grind with fine diamond sand, requiring the two end surfaces to be parallel and perpendicular to the axis, and the final length should be 10±0.1mm. 3.3 Accurately measure the diameter and length of the sample and record them. 2
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GB9622.8-88
3.4 Anneal the sample to eliminate stress. Clean with distilled water and anhydrous ethanol and dry. Apply low-temperature silver paste to both ends, heat to 460-500℃ in a high-temperature furnace, keep warm for 10 minutes, and then slowly cool to room temperature. The surface silver layer should be tight and even, and have good conductivity. Finally, use fine sandpaper to grind off the silver layer on the edge, and then clean it with anhydrous ethanol. 4 Test steps
4.1 Place the sample on the active electrode of the device, cover the heat dissipation cover, put the heating furnace outside the active electrode, connect the electrode, and put the thermometer through the center hole of the heat dissipation cover into the center of the measuring base. 4.2 Turn on the galvanometer and adjust the zero point.
4.3 Turn on the power of the electric furnace, adjust the heating speed, and heat at a uniform speed of 2-3℃/min. 4.4 Turn on the measuring power supply and apply DC voltage to the sample. 4.5 The starting point of the measurement is generally 30-40℃ lower than the predetermined T-100 of the glass. Keep the temperature for 10 minutes, start measuring, and record the test temperature, the voltage applied to the sample, the current passing through the sample, and the blank current. 4.6 Continue to increase the furnace temperature, and measure once every 10℃ increase until the temperature is 30-40℃ higher than the T-100 of the glass, and then end the test. 5 Calculation
5.1 Use formula (2) to calculate the actual current passing through the sample I=I-lo
Where: I—actual current passing through the sample, A, I. Measure the current passing through the sample, A,
I blank test current, A.
5.2 Calculate the volume resistivity using formula (3)
P=VS/IL
Where: p is the volume resistivity of the sample, Q·cm, V is the applied voltage, V
1 is the actual current passing through the sample, A;
s is the cross-sectional area of the sample, cm
L is the length of the sample, cm.
5.3 Calculate 1/T using formula (4)
Where: T is the thermodynamic temperature, K,
t is the measurement temperature, °C,
5.4 Calculate T--100
Plot the 1/T-1gp relationship diagram of the measured and calculated data on the coordinate paper, with the horizontal axis representing 1/T and the vertical axis representing 1gp, and obtain the corresponding points, connecting the points into a straight line. This straight line intersects with the straight line 1gp=8. The 1/T corresponding to the intersection is converted into t by formula (4), which is T-100, as shown in Figure 3.
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6 Test results
GB9622.8-88
Relationship diagram with 1gp
T#—100
This method allows the measurement error to be ±1°C. When the difference between the data of two parallel measurements of the same batch of samples is within this range, the average value is taken as the test result.
Additional notes:
This standard was drafted by Factory 4404, Factory 4400 and the Standardization Research Institute of the Ministry of Electronics Industry. The main drafters of this standard are Luo Shenghua, Bai Yixiang, Pang Shuqin and Liu Chengjun. YYKAONTKACa
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