The ASTM D7739 standard is titled "Measurement of Thermal Oxidation Stability Using Quartz Crystal Microbalance."
Despite the fact that the ASTM D2 committee has officially released the ASTM D7739 standard, EUCA Technology Co., Ltd. has launched a commercial instrument, the 7739 Type Tester, which fully complies with the ASTM D7739 standard and has been successfully applied in the Petrochemical Science Research Institute of China Petroleum & Chemical Corporation.
According to the standard measurement procedures stipulated in ASTM D7739, the following technical routes are available for the instrument:
quartz crystal is paired with a gold electrode and immersed in the test oil in the reactor. The oscillator is connected to the quartz crystal to provide vibration energy and detect the quartz crystal's resonance frequency, whose vibration duration is controlled by the computer. The reactor is equipped with a magnetic stirrer, a pressure transmitter, an oxygen sensor (optional), and a thermocouple for monitoring test conditions. Before the test, the oil sample is ventilated for 30 minutes to achieve oil-gas equilibrium (saturation). Then the reactor is isolated, and the temperature and pressure are raised to the test requirements. During the test, as the deposited material accumulates on the crystal surface, the crystal frequency will decrease. The resonance frequency is adjusted in real time according to the deposited material quantity, and the deposited material quantity is quantitatively calculated by the Sauerbrey formula.
The system provides a qualitative evaluation of jet fuel, lubricating oil, and other hydrocarbon liquid products in terms of their catalytic cracking or partial oxidation to generate substances and consume oxygen at high temperatures. Additionally, the system can also be used to evaluate the effects of lubricants or other hydrocarbon liquid products (such as gasoline and diesel) on the formation of residues or resistance to slow partial consumption by air at high temperatures.
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自主研发，导航式界面，自动测试！
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量程范围
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0~30μg/cm2
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测试分辨率
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0.3μg/cm2
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反应器容积mL
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100
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标准测试温度°C
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140±0.2
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可选最高测试温度
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400±0.5
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实验压力
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100~200 psig
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