Halogen Acid Gas Test

• Objective
Determine amount of halogen acid gas evolved during the combustion of compounds based on halogenated polymers and compounds containing halogenated additives taken from electric or optical fire cable constructions.
• Reference Standard
IEC 60754-1Test on gas evolved during combustion of materials from cables.
Part 1 Determination of the halogen acid gas content.
• Test Detail
A sample consist of 500 mg to 1000 mg shall be stored at least 16 h at a temperature of 23 ± 2°C and relative humidity 50 ± 5%.
The sample is heated in a stream of dry air at uniform heating rate increase over a time of 40 min ±5 min and maintain at 800° c ± 10°c for 20 min and the gases absorbed in 0.1 M sodium hydroxide solution. The amount of halogen acid gases is then determined by acidifying the solution with nitric acid, adding a measured volume of 0.1 M silver nitrate solution and back titrating the excess with 0.1 M ammonium thiocyanate using ferric ammonium sulphate as the indicator.
Calculate the amount of halogen acid.