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1、International Standard 6992 0 4Yli 4 INTERNATlONiL ORGANIZATION FOR STANDARDlZATlONMEXAYHAPOHAR OPFAHMBAl - mercury and its derivatives. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/2
2、8/2007 07:01:34 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 6992-1986 03 Section one : Test methods 2 Principle Pre-washing of test pieces during a fixed time. Filling the test pieces with water acidified with carbon dioxide. Determination of the quantities of cadmi
3、um, mercury and their derivatives. NOTE - The analytical test methods to be used for the determination of the quantity of material taken into solution are not defined. They should, however, allow the analysis to be carried out with an accuracy of 0,005 mg/l for cadmium and of 0,000 5 mg/l for mercur
4、y. 3 Apparatus 3,l Glass tube with glass stopcock 3.2 Stoppers in polyethylene or any other material which has been shown not to affect the results. 3.3 Stoppered glass containers. 4 Reagents 4.1 Test water, distilled water acidified to a pH of 4,5 f 0,l by bubbling carbon dioxide through the water,
5、 4.2 Distilled water. 5 Preparation of test pieces For each test, select three pieces of the pipe at random, each of which is 500 mm in length and has an internal volume at least equal to the volume of the extracting liquid required to deter- mine with the required precision the amount of material w
6、hich has migrated. NOTE - The dimensions of the pipe should be indicated in the prod- uct standards. 6 Procedure 6.1 Pm-washing 6.1.1 Close one end of each test piece with a stopper (3.2) fitted centrally with a length of glass tube (3.1) with a stop- cock. 6.1.2 Clamp the test pieces vertically wit
7、h the open end up wards. 6.1.3 Pass tap water of pH 7 to 8 through the test pieces so that its linear rate of flow is 3 m/min, calculated from the average internal cross-sectional area of the pipe, and the test pieces shall be continuously filled with tap water. 6.1.4 Maintain the water flow for a p
8、eriod of 60”: min. 2 6.1.5 At the end of this period, stop the water flow, remove the stoppers and rinse out the test pieces with distilled water (4.2). 6.2 Extractability test For each series of tests, freshly prepared test water (4.1) shall be used. 6.2.1 Close, with a stopper (3.2), one end of ea
9、ch pre-washed test piece. 6.2.2 Fill each test piece with test water (4.11, the temperature of which has been adjusted to approximately 20 T. 6.2.3 Close the other end of each test piece by means of a stopper (3.2) and maintain the filled test pieces at 20 Z!I 2 OC for 48 h. 6.2.4 At the end of 48 h
10、, empty the test water from each test piece into separate stoppered glass containers (3.3). These are the first extracts on which the quantities of cadmium and mercury and their derivatives shall be determined. 6.2.5 Fill each of the same test pieces, stoppered at one end, with fresh test water at 2
11、0 + 2 OC. Close the other end with a stopper and leave at 20 f 2 OC for 48 h. At the end of 48 h, empty the test water from each test piece into separate stoppered glass containers (3.3). These are the second extracts on which the quantities of cad- mium and mercury and their derivatives shall be de
12、termined. 6.2.6 Fill each of the same test pieces, stoppered at one end, with fresh test water at 20 f 2 OC. Close the other end with a stopper and leave at 20 f 2 OC for 48 h. At the end of 48 h, empty the test water from each test piece into separate stoppered glass containers (3.31. These are the
13、 third. extracts on which the quantities of cad- mium and mercury and their derivatives shall be determined. 7 Expression of results 7.1 Cadmium 7.1.1 Calculate the arithmetic mean of the quantity of cad- mium found in the three test waters at each extract. 7.1.2 Express the results in milligrams pe
14、r litre, to the nearest 0,065 mg/l. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:01:34 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 6992-19
15、66 (EI 7.2 Mercury 7.2.1 Calculate the arithmetic mean of the quantity of mer- cury found in the three test waters at each extract. 7.2.2 Express the results in milligrams per litre, to the nearest 0,000 5 mg/l. 6 Test report The test report shall include the following information : a) complete iden
16、tification of the pipe tested; b) the number of test pieces; c) the analytical method used for the determination of the quantity of cadmium in aqueous solution: d) the analytical method used for the determination of the quantity of mercury in aqueous solution; e) the duration of the pre-washing; f)
17、the quantities of extracted cadmium found for each test piece for the first, second and third extractions; g) the arithmetic mean of the quantities of extracted cadmium for the pipe for the first, second and third ex- tractions: h) the quantities of extracted mercury found for each test piece for th
18、e first, second and third extractions; i) the arithmetic mean of the quantities of extracted mercury for the pipe for the first, second and third ex- tractions; j) details of the procedure which have not been provided for by this test method and also any accidental cir- cumstances which might have a
19、ffected the results. Section two : Basic specification Under the arduous test conditions for extractability described in section one, the extracted quantities of cadmium and mercury shall not exceed the values given in clauses 9 and 10 respectively. 9 Cadmium For all three extracts, the cadmium conc
20、entration shall not be greater than 0,Ol mg/l. 10 Mercury For all three extracts, the mercury concentration shall not be greater than 0,001 mg/l. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:01:34 MDTNo reproduction or networking permitted without license from IHS -,-,-