Wire and cableTest method for smokeσ↕ density and halogen content dete≈ &®ction:

IEC 61034-1/ASTM E662 Emission of S&≥↑moke. This is the specification f ​• or smoke density in IEC ÷‍∏™and ASTM standards. The ←∑experiment consists of a 3m3 cube and a™≈ photometric measurement syst♣£​​em with a light source, with alc ≠"ohol inside a rectangular §§slot as the combustion sour→₩✔ce. A blower with a power of 10-15 m3/ ₽min ensures that smoke is ♥☆≤evenly distributed on a windsh×✔<•ield to prevent flame vortices from forφ♦☆←ming on the grooves. When alcohol♥ ​ burns, a recorder co♠ nnected to the optical↕​∑ power source records the am≥>✘ount of light attenuation>α↕←. Smoke density is measured ♣¶by light transmittance. If i→≠‍t can achieve a light tra  "nsmission value of 60%, th♦‌₹₽e cable material will meet the low ÷δ≥smoke standard. The higher t®→★→he light transmittance, the less smo←σke the material releλλases during combustion.

ISO4589-2/BS2863 Oxygen Index LOI

This is the specificati‍☆ €on for oxygen index in ISO and BS stand₩αδards. It refers to the sitφφuation where at room temperatur↑&e, when the oxygen content of the aΩ£↔ir in the cable supply exceeds t← ‍εhis oxygen index, the maσ↓∏terial will immediately burn. Thσ$e higher the oxygen i∞  ✔ndex value, the more flame retε♦ardant the material is. If th§λλ​e oxygen index of a materi→‌​al is 21%, it means that the mater‌→≈ ial will automatically burn a  ₹t normal room temperature. ☆♥At normal room temperature, the oxygen ¶π®content of air is 21%. Generally, the  λΩ"oxygen index of flame-retardant ca₩​bles is greater than≥"£ 33%. IEC60754-2 Gas ←αAcidity Measurement (Corrosion) ±≤is used to measure the acidity of h∞φalogen acid gas produced by the mater$↕÷σial during combustion. ✘≈≈It is determined by the pH value an≤× d conductivity of the aqueous solution.πφ According to the experim★α<ental regulations, preheat th'≠e combustion furnace to 80↔$ 0 ℃, push a quartz tube with a built-©∑in sample into the furnace, an£β≠∞d start timing at the same time. M​®∏ easure the pH value and electr‌β∏ical conductivity every 1 ←↔&↑minute during the firs∑>φ×t 5 minutes of sample co ®±mbustion, and every 5 minutes for÷≥ the next 25 minutes.♣   The pH value of gene λ✘ral halogen-free cable mate→≥€rials will be greater than 4.≥®​Ω3, and the conductivity will be less t★₩<han 10 μ s; The lower the pH™©★ value, the higher the a"​cidity of the halogen acid gas÷π∑ in the material. It is worth noλ§×ting that when the HCL content is gr™✘→eater than 2mg/g but less than♥  5mg/g (i.e. meets the requiremenΩ"ts of IEC60754-1), the pH value of →™its aqueous solution i♦§£∑s also less than 4.3, whiΩ±β≥ch does not meet the requirement™£s of IEC60754-2.

IEC60754-1/BS6425-1 Determinat$÷≤ion of Halogen Gas Content (Emi​<₹™ssion of Halogens)

This is the specification for h↑♠≠≈ydrogen chloride (HCL)$≠ release concentratio®δ©±n in IEC and BS standards. H×&≈alogens contain fluorine (Florinε$e), chlorine (Chlorine), bromine ® ✘(Bromine), iodine (Iodine)§©, and the radioactive vol'∏¶γatile element astati§"ne (Astatine), which have h£ε÷igh toxicity. According to÷☆®  the experimental regulations, when theΩ↑σ combustion furnace is preheated to 80☆±¶Ω0 ℃, a 1.0g sample is inserted int÷¥o the furnace, and the HCL₩β♦‌ is dissolved in water using ₽✔the airflow discharge rat↑★"✔e. Then, the halogen acid✘$ content of the aqueous so♣¥lution is measured. If the release o​βf halogen acid during cable material cβ¥‌ombustion is less than♥" ® 5mg/g, it can be called halogen-free  ±εcable (LSOH). If the release o£<f halogen acid (HCL) is gre←↕ater than 5mg/g but le<™ss than 15mg/g, it can be called low ✘♥halogen cable (LSF).‍♠§♣ It is worth noting that the I☆'πEC60754-1 method cann♦π'λot be used to determineδ↔ ¥ materials with HCL content less> §© than 5 mg/g, that is, it cannot dete&$rmine whether they areδ♣≈↑ "halogen-free". The IEC60754-2φ©‌ method can be used to determ䙥ine whether it is completely halogen-frα §ee.