The High Temperature Oxygen Index (LOI) is an indicator for evaluating the flammability of materials in a high temperature oxygen environment. The high temperature oxygen index tester is a device used to determine the LOI value of materials. The following are the steps of a common high temperature oxygen index tester experimental method:
1. Sample preparation:
a. Select a sample that meets the test requirements, and cut the sample into an appropriate size and shape according to the standard requirements. Typically, the size of the sample is 130mm x 6.5mm x 3.2mm and the shape is rectangular.
b. Surface treatment of samples with appropriate methods, such as removal of dirt, oxide layer, etc., to ensure the accuracy of test results.
2. Sample installation:
a. Fix the sample on the test device, making sure that the surface of the sample is flat and in good contact with the clamps of the test device.
b. Make sure there is no gap between the edge of the sample and the clamp to prevent oxygen leakage.
3. Preheating:
a. Turn on the high temperature oxygen index tester and set the temperature controller to the test temperature (usually 850°C).
b. Wait for the tester to reach a stable temperature and ensure the accuracy of the temperature controller.
4. Oxygen supply:
a. Pass oxygen into the combustion chamber of the tester to ensure sufficient oxygen supply during combustion.
b. Adjust the oxygen flow to meet the standard requirements and ensure the stability of the oxygen flow.
5. Ignition and combustion:
a. Use an ignition device to ignite one end of the sample and observe whether it can spontaneously ignite.
b. If the sample cannot spontaneously ignite, use an ignition device to ignite one end of the sample, make sure that the ignition source touches the sample, and observe whether the sample can continue to burn.
c. Record the time required to ignite the sample, and observe the characteristics of the combustion, such as the color of the flame, the speed of burning, etc.
6. Test result record:
a. According to the standard requirements, record the sample ignition time and burning time.
b. Calculate the high temperature oxygen index (LOI) value of the sample according to the burning length of the sample during the combustion process.
7. Clean and prepare for the next test:
a. Turn off the oxygen supply and ignition and wait for the test device to cool.
b. Clean the test fixture and fixtures in preparation for the next test.
It should be noted that the above steps are only a common experimental method of high temperature oxygen index tester, and the specific experimental steps may vary according to different test instruments and standard requirements. When performing high-temperature oxygen index testing, it should be operated in strict accordance with relevant standards and specifications, and the accuracy and stability of the testing equipment should be ensured. In addition, in order to obtain reliable test results, attention should also be paid to the influence of factors such as sample selection, preparation and handling.