According to GB/T17651.1~2 and IEC61034-1~2,the first parts of "test device" and second part of "test steps and requirements" for the determination of smoke density of cables or optical cables under specific conditions. The determination of smoke density is an important aspect of assessing the combustion characteristics of cable or cable, which is related to the evacuation of the personnel and the determination of the proximity of the fire extinguishing. This instrument is mainly used to determine the smoke concentration of cables and optical cables under specific conditions and to verify the smoke density. Under the conditions of flame burning or flameless combustion, the transmittance is used as a way to compare different cables or cables under specific conditions.

1.Feature

 This instrument relates to three aspects of mechanical, optical and electronic expertise. It is a mechanical and electrical integration product. It has the advantages of reasonable structure, stable performance and easy operation. WINDOWS XP operation interface, LabVIEW style and perfect security mechanism. During the test of real-time display measurement results and dynamically draw a perfect curve (through the display rate and time curve), the data can be stored permanently, read and print output, can directly print the report.

Measurement software: It is main data of smoke and light density, specific optical density, smoking rate, maximum smoking rate and average smoke density can be tested at WINDOWS XP+VB6.0 operation interface. It also has the operating interface of calibration, editing, testing, parameter adjustment and so on. The program uses computer automatic control, collection, recording and result settlement. 

2.Principle

 The light measurement system for the smoke density of cable or optical cable under specific conditions is composed of light source, silicon photocell, light source receiver and computer system. The light generated by the light source passes through the smoke density Laboratory of 3M * 3M * 3M, forming 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 intensity of the beam from the light source. When the combustion chamber due to combustion of cables to produce a lot of smoke, the smoke of photoelectric absorption, achieve the silicon photocell beam intensity is weakened by the computer system for data processing, we can calculate the relative to the initial 100% with linear response light transmittance.

The design of the combustion chamber, two ways for customers to choose: the first one uses the brick wall, Our company provide the design scheme, send professional engineers to guide the construction site; second with suitable material is fixed on the angle iron bracket and the whole cube combustion chamber.

3.Equipment composition

The whole instrument is composed of closed test box, photometer measuring system, alcohol disk, combustion system, igniter, test box, cable bracket, temperature measuring instrument and smoke density testing software. The circuit is developed by single chip microcomputer with high technology content and stable performance. This instrument is suitable for all cables. It is widely used by production plants of wire and cable industry and research and test units. The test box is a test cube with a volume of 27m3.

4.Detailed technical parameters

5.Other parameters and introduction

 a.The front door is equipped with windows and opaque visions that can block the inspection activities.

b.The bottom of the square box is equipped with an automatic ignition device, and the top is installed with the internal pressure regulating device of the box.

c.Light source: incandescent lamp for 12V, light wavelength from 400 to 750nm.

d.Acceptor: for silicon photocell, the transmittance of 0% is passed without light and the transmittance rate is 100% light without occlusion.

e.Combustion system: composed of pressure regulating valve, filter, regulating valve flowmeter and burner.

f.Burner: made up of an igniter and an alcohol disk and placed in the center of the sample.

6.Main configuration