3 Metre Cube Smoke Density Tester

1. Scope of application:

1.1 It is used to measure the density of smoke released when cables and optical cables are burned under specific conditions.

2. Compliant standards:

2.1 Compliance with IEC 61034-2:2019 "Measurement of smoke density of cables burning under defined conditions—Part 2: Test procedure and requirements, IDT"

2.2 Compliance with IEC 61034-1:2019 "Measurement of smoke density of cables burning under defined conditions—Part 1: Test apparatus, IDT"

3.1 Under specific conditions, the burning smoke density light transmission test system consists of a light source, a silicon photocell receiver and a computer system. The light generated by the light source passes through the smoke density laboratory of 3m×3m×3m, and forms a uniform beam with a diameter of 1.5m±0.1m on the wall opposite the light source. The photocell installed at the center of the beam detects the beam intensity from the light source. When a large amount of smoke is generated in the combustion chamber due to burning cables or optical cables, the smoke absorbs a part of the light, and the intensity of the beam reaching the silicon photovoltaic cell is weakened. By processing the data with a computer system, it is possible to calculate the transmittance with a linear response relative to the initial 100%.

3.2 Combustion chamber:

3.2.1 Use SUS304 stainless steel with a thickness of 1.5mm to be fixed on a square bracket to form the entire cubic combustion chamber.

3.2.2 Internal dimensions: L3000*W3000*H3000(mm)

3.2.3 Structure: There is a glass observation window on the front, and a transparent sealing window on the opposite walls on both sides. The size is 100mmx100mm, allowing the beam of the horizontal photometer to pass through. The height of the center of the sealing window from the ground is 2150mm. There are several ventilation holes at the bottom and the ventilation holes are 100x500mm (50 square centimeters)

3.2.4 The top is equipped with an exhaust fan.

4. Optical test system:

4.1 The light source is an imported quartz halogen lamp. Nominal power: 100W; Nominal voltage: 12V Accuracy: ±0.01V; Nominal luminous flux: 2000～3000Lm, Nominal color temperature: 2800K～3200K, which meets the requirements of GB/T17651.1 5.2.

4.2 The light transmittance of 0% means that no light passes through, and the light transmittance of 100% is completely unobstructed.

4.3 Measurable transmittance range (0～100)%;

5. Standard fire source:

5.1 The fire source is 1.0L alcohol configuration: 90% ethanol, 4% methanol, 6% water

5.2 Alcohol plate (burning boat): stainless steel thickness 1.0mm, bottom surface: 210x110mm, top surface: 240x140mm, height 80mm;

5.3 Installation position: The height between the alcohol tray and the ground is 100mm, so that the air can be circulated.

6. Mix of smoke:

6.1 Use a desktop fan to distribute the smoke evenly in the combustion chamber. The height of the fan shaft is 250mm from the ground, 500mm from the wall, and the air volume is 7 cubic meters per minute. Air is blown horizontally by a fan during the test.

7. Temperature measuring device:

7.1 A temperature sensor is installed on the inside of the door at a height of 1.5M from the ground and 0.5M from the wall. The temperature of the laboratory can be monitored.