Requirements for the setting of the limit oxygen index test sample

Summary of test methods:

The sample is vertically fixed in a transparent combustion tube of an upward flowing oxygen and nitrogen mixed gas, ignites the top of the sample, observes the combustion characteristics of the sample, and compares the continuous burning time of the sample or the burning length of the sample with a given limit value. The minimum oxygen concentration value expressed as a percentage of oxygen at the time of combustion was measured by a series of tests at different oxygen concentrations.

Size of the test specimen and size and position requirements of the film or sheet specimen holder: As shown in the figure: If it is a stick specimen, the tip of the specimen is 100 mm from the top of the burner cylinder, and the bottom distance of the specimen is filled. The glass beads are also 100 mm, and the top cover has a hole diameter of 40 mm and a thickness of 10 mm.Following table shows the dimensional requirements of the sample:

Test specimen type	Length(mm)	Width(mm)	Thickness(mm)	Material form
Ⅰ	80 to 150	10±0.5	4±0.25	Molding materials
Ⅱ	80 to 150	10±0.5	10±0.5	Cellullar materials
Ⅲ	80 to 150	10±0.5	≤10.5	Sheet materials
Ⅳ	70 to 150	6.5±0.5	3±0.25	Sheet or molding materials
Ⅴ	140±5	52±0.5	≤10.5	Flexible film or sheet materials
Ⅵ	140 to 200	20	0.02 to 0.10	For thin film that can be rolled by the wire specified in 6.8

The following pictures shows the relevant dimensions of the film or sheet sample holder:

The sample holder consists of two open plates with a total height of 140 mm and a width of 51 mm. The bottom has an open frame holder.

Scope of application:

Suitable for the determination of the burning properties of plastics, rubber, fiber, foam plastic, film and textile materials,etc.

Main technical parameters:

1. Using precise oxygen sensor, the digital display shows the oxygen concentration without calculation, the accuracy is higher and more accurate, the range is 0-100%

2. Digital resolution: ±0.1%

3. Input pressure: 0.2-0.3MPa

4. Flow adjustment range: 0-10L/min (60-600L/h)

5. Response time: <5S

6. Quartz glass cylinder: inner diameter ≥75mm high 300mm

7. Gas flow rate in the combustion cylinder: 40mm ± 2mm / s The total height of the combustion cylinder is 450mm

8. Pressure gauge accuracy 2.5, resolution: 0.01MPa

9. Flowmeter: 1-15L/min (60-900L/H) adjustable, accuracy 2.5

10. Test ambient environment: room temperature ~ 40℃; relative humidity: ≤ 70%;

11. Maximum operating power: 50W

12. Working pressure: nitrogen 0.05-0.15Mpa Oxygen 0.05-0.15Mpa Oxygen/nitrogen mixed gas inlet: including pressure regulator valve, flow regulating valve, gas filter and mixing chamber.

13. Sample holders can be used for soft and rigid plastics, textiles, fire doors, etc.

14. Propane (butane) ignition system, flame length 5mm-60mm can be adjusted freely

15. Gas: industrial nitrogen, oxygen, purity >99%; (user-supplied).

16. Power requirements: AC220 (+10%) V, 50HZ

17. Igniter: It has a metal tube and a nozzle with an inner diameter of Φ2±1mm at the end. It can be inserted into the combustion tube to ignite the sample. The flame length is 16±4mm and the size is adjustable.

18. Non-self-supporting material sample holder: can fix two vertical sides of the sample to the frame at the same time

19. Self-supporting material sample holder: can be fixed at the axial position of the combustion tube and can clamp the sample vertically