I. Summary
GD-6541A Interfacial Tension Meter is designed and made as per the National Standard of People’s Republic of China GB/T6541-86 (1991) “Test Method for Interfacial Tension of Oil against Water by the Ring Method”. It is suitable to determine the interfacial tension between mineral oils and water under non-equilibrium condition (Liquid-Liquid interface). It can also be used to determine interfacial tension of various liquids (Liquid-Gas interface).
GD-6541A Interfacial Tension Meter adopts large LCD screen and blank button, so it is automatic, reliable, and simple and with good repeatability. Turn on the instrument and operate the instrument as per the prompt of menu, and you can complete the test as per the prompt. The instrument has function of automatic temperature compensation, clock control, printing, and automatic average value calculation. It can connect to a computer through RS232 interface. You can also send the test data to a handheld computer for analysis. It is the best choice to make determination for interfacial tension test.

II. Main technical specifications and parameters
1. Display method: It has a large LCD screen with background light and prompt menu. The menu contains all test procedures and calculation methods stipulated in the GB/T6541.
2. Buttons: Blank buttons
3. Measurement range:
   (1) For insulating oil: 2~100 mN/m
   (2) For other petroleum products: 2~200 mN/m
4. Sensitivity: 0.1 mN/m
5. Accuracy: 0.1 mN/m
6. Resolution: 0.1 mN/m
7. Repeatability: 0.3%
8. Ambient temperature: 10°C~30°C
9. Relative humidity: 20%~75%
10. Power supply: AC 220V±5%, 50 Hz
11. Rated power: ≤ 100 W
12. Size: 185 mm×260 mm×360 mm
13. Weight: 15 kg