Oxygen Index Tester - Test procedure for surface combustion method

The Oxygen Index Tester is an instrument for determining the combustion properties of substances. It is used for the evaluation of the fire performance of various types of fireproof materials, flame retardant materials, coatings, etc., the classification of flammability classes of chemical products, and the application area of exploring the combustion performance of certain special substances.

Instrument structure:

A complete test of the burning properties of insulating liquids - Oxygen Index Tester consists of a quartz glass combustion cylinder, test disc, test disc support, flow measurement and control device, ignition source, paramagnetic or chemical oxygen sensor, timer, smoke exhaust system.

Test methods:

(1) wick method in the specimen immersed in an inert material (such as glass wire, asbestos wire, etc.) made of wick , the

Ignition only let the wick ignite .

(2) surface combustion method, also known as the wickless method, ignition, the igniter against the entire surface of the liquid specimen, so that the entire surface are burning.

Surface combustion method of 8 test steps:

1, the instrument will be placed in (23 ± 2) ℃ room

2, remove the glass burning cylinder, ensure that the test disc support in the center axis of the burning cylinder as shown in Figure 1, the apex of the support to install a clean test disc.

3、Turn on the power, turn on the power switch

4, with a pipette to inject the specimen into the test disk until the liquid surface of the curved liquid level below the disk mouth 1mm.

5, according to the test experience of similar liquids, choose the appropriate starting oxygen concentration. If the lack of experience, then ignite the specimen in the air and pay attention to the combustion situation. If the specimen burns, the starting oxygen concentration is about 18%: If the specimen does not burn, the starting oxygen concentration is about 25%

6, adjust the oxygen and nitrogen controller to obtain the required oxygen concentration. The total gas flow rate (cm3/s) divided by the cross-sectional area of the combustion brief (cm2) to calculate the gas flow rate within the combustion brief should be (4 ± 1) cm / s. Blow the test system with airflow for at least 30 s.

7, as shown in Figure 2, let the igniter flame all cover the surface of the liquid specimen until the liquid ignites, and then remove the igniter.

If you burn less than 60s flame out that the oxygen concentration is too small, you should increase the oxygen concentration, re-exchange the liquid specimen, repeat the test in a larger oxygen concentration

Note: If the liquid does not ignite, the liquid can be used, do not need to be replaced.

8. If you get a stable combustion and continue for more than 60s, that is, the oxygen concentration is too large, should be reduced. Use a clean test plate to reload the new specimen, in a smaller oxygen concentration to repeat the test. Until the minimum oxygen concentration that can just maintain the liquid burning 60S or a little more time, and when the oxygen index concentration value of 0.5% lower, the specimen burning less than 60s.

Oxygen index to determine the burning characteristics of the material and the risk of fire important physical and chemical parameters. Due to the needs of industry testing standards, QINSUN Instruments has developed both the Oxygen Index Tester for testing the combustion performance of solids and the oxygen index value for measuring the combustion of liquids.

2022-08-23 10:59