IEC 60754-2011 pdf free download – Test on gases evolved during combustion of materials from cables – Part 1: Determination of the halogen acid gas content.
This part of lEC 60754 specifies the apparatus and procedure for the determination of theamount of halogen acid gas,other than hydrofluoric acid,evolved during the combustion ofcompounds based on halogenated polymers and compounds containing halogenatedadditives taken from electric or optical fibre cable constructions.
NOTE 1 This test method is not able to determine hydrofluoric acidA suitable method may be found inlEC 60684-2.
NOTE 2 This test method may be used to test materials to be used in cable manufacture, but a declaration ofcable performance should not be made based on such a test.
NOTE 3 The relevant cable standard should indicate which components of the cable should be tested.
NOTE4 For the purposes of this standard, the term “electric cable” covers all insulated metallic conductor cablesused for the conveyance of energy or signals.
The method specified in this standard is intended for the testing of individual componentsused in a cable construction. The use of this method will enable the verification ofrequirements which are stated in the appropriate cable specification for individual componentsof a cable construction.
NOTE 5 By agreement between the producer and purchaser, the methodology given in this standard may be usedto test combinations of materials representing a cable construction, but a declaration of cable performance to thisstandard should not be made based on such a test. Information on such a method is given in Annex A.
For reasons of precision this method is not recommended for reporting values of halogen acidevolved less than 5 mg/g of the sample taken.
2Normative references
The following referenced documents are indispensable for the application of this document.For dated references,only the edition cited applies. For undated references, the latest editionof the referenced document (including any amendments) applies.
ISo 385,Laboratory glassware – Burettes
ISO 1042,Laboratory glassware – One-mark volumetric flasks
lso 3696,Water for analytical laboratory use – Specification and test methods
3Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
halogen acid gas content
amount of halogen acid gas evolved,except hydrofluoric acid，expressed as milligrams ofhydrochloric acid per gram of total test specimen
4Test method principle
The material under test shall be heated in a stream of dry air and the gases shall be absorbedin 0,1 M sodium hydroxide solution contained in wash bottles. The amount of halogen acidshall then be determined by acidifying the solution with nitric acid, adding a measured volumeof 0,1 M silver nitrate solution and back titrating the excess with 0,1 M ammoniumthiocyanate, using ferric ammonium sulphate as the indicator.
NOTE 1 Other analytical methods having at least the same precision may be used, but in case of dispute themethod given in this standard is the one to use.
NOTE 2 Although both hydrogen chloride and hydrogen bromide are detected by this analytical method, thehalogen acid content is reported as if all the halogen acid is hydrogen chloride.
5 Test apparatus
5.1 General
The apparatus is shown in Figures 1 to 5.
The assembly of the components which constitute the test apparatus shall be leak-tight. Theconnecting distances between the quartz glass tube and the first bottle and betweensubsequent bottles shall be as short as possible.Glass or silicone rubber tubing shall be usedfor these connections.
NOTE 1 At the exit side of the quartz glass tube, as close to the end as possible, it is permitted to place a plug ofsilica wool to aid collection of condensates.
NOTE 2 A third empty bottle, of the same size as the gas washing bottles, placed before the gas washing bottles,may be used to improve safety, i.e. to prevent suck back of water into the quartz glass tube.
5.2Tube furnace
The length of the heating zone of the furnace shall be within the range 480 mm to 620 mm,and its inside diameter shall be within the range 38 mm to 62 mm. It shall be equipped with anadjustable electrical heating system.
5.3Quartz glass tube
For the test, a quartz glass tube shall be introduced into the tube furnace.The tube shall beapproximately concentric to the furnace. lt shall be resistant to the action of corrosive gases.
The inside diameter of the tube shall be within the range 30 mm to 46 mm.The tube shallprotrude on the entrance side of the furnace by a length of between 60 mm to 200 mm, andon the exit side by between 60 mm to 100 mm.The initial clearance shall allow for thermalexpansion.For the purposes of measurement of the protrusion distances，the tube shall beregarded as that part of essentially constant diameter.
NOTE The outer diameter of the tube should be chosen with due regard to the inside diameter of the tubefurnace.
Prior to each test,the tube shall be cleaned throughout its length by being calcined atapproximately 950 c.IEC 60754 pdf download.