定价： 1840元 / 折扣价： 1638 元 加购物车

定价： 1840元 / 折扣价： 1638 元 加购物车

定价： 541元 / 折扣价： 482 元 加购物车

定价： 3204元 / 折扣价： 2852 元 加购物车

定价： 5451元 / 折扣价： 4852 元 加购物车

定价： 2081元 / 折扣价： 1853 元 加购物车

定价： 1099元 / 折扣价： 979 元 加购物车

定价： 1656元 / 折扣价： 1474 元 加购物车

定价： 1473元 / 折扣价： 1311 元 加购物车

定价： 1473元 / 折扣价： 1311 元 加购物车

定价： 1656元 / 折扣价： 1474 元 加购物车

5.1 These test methods are used to chemically determine the maximum quantity of oxygen that could be consumed by biological or natural chemical processes due to impurities in water. Typically this measurement is used to monitor and control oxygen-consuming pollutants, both inorganic and organic, in domestic and industrial wastewaters.5.2 The relationship of COD to other water quality parameters such as TOC and TOD is described in the literature.31.1 These test methods cover the determination of the quantity of oxygen that certain impurities in water will consume, based on the reduction of a dichromate solution under specified conditions. The following test methods are included:  Test Method A — Macro COD by Reflux Digestion and Titration  Test Method B — Micro COD by Sealed Digestion and Spectrometry1.2 These test methods are limited by the reagents employed to a maximum chemical oxygen demand (COD) of 800 mg/L. Samples with higher COD concentrations may be processed by appropriate dilution of the sample. Modified procedures in each test method (Section 15 for Test Method A, and Section 24 for Test Method B) may be used for waters of low COD content (<50 mg/L).1.3 As a general rule, COD results are not accurate if the sample contains more than 1000 mg/L Cl−. Consequently, these test methods should not be applied to samples such as seawaters and brines unless the samples are pretreated as described in Appendix X1.1.4 This test method was used successfully on a standard made up in reagent water. It is the user’s responsibility to ensure the validity of these test methods for waters of untested matrices.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 8, 15.6, and 24.5.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 646元 加购物车

定价： 646元 加购物车

5.1 This test method provides for the measuring of the minimum concentration of oxygen in a flowing mixture of oxygen and nitrogen that will just support flaming combustion of plastics. Correlation with burning characteristics under actual use conditions is not implied.5.2 In this test method, the specimens are subjected to one or more specific sets of laboratory test conditions. If different test conditions are substituted or the end-use conditions are changed, it is not always possible by or from this test to predict changes in the fire-test-response characteristics measured. Therefore, the results are valid only for the fire-test-exposure conditions described in this test method.1.1 This fire-test-response standard describes a procedure for measuring the minimum concentration of oxygen, expressed as percent volume, that will just support flaming combustion in a flowing mixture of oxygen and nitrogen.1.2 This test method provides three testing procedures. Procedure A involves top surface ignition, Procedure B involves propagating ignition, and Procedure C is a short procedure involving the comparison with a specified minimum value of the oxygen index.1.3 Test specimens used for this test method are prepared into one of six types of specimens (see Table 1).1.4 This test method provides for testing materials that are structurally self-supporting in the form of vertical bars or sheet up to 10.5-mm thick. Such materials are solid, laminated or cellular materials characterized by an apparent density greater than 15 kg/m3.1.5 This test method also provides for testing flexible sheet or film materials, while supported vertically.1.6 This test method is also suitable, in some cases, for cellular materials having an apparent density of less than 15 kg/m3.NOTE 1: Although this test method has been found applicable for testing some other materials, the precision of the test method has not been determined for these materials, or for specimen geometries and test conditions outside those recommended herein.1.7 This test method measures and describes the response of materials, products, or assemblies to heat and flame under controlled conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials, products, or assemblies under actual fire conditions.1.8 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific hazards statement are given in Section 10.1.10 Fire testing is inherently hazardous. Adequate safeguards for personnel and property shall be employed in conducting these tests.NOTE 2: This test method and ISO 4589-2 are technically equivalent when using the gas measurement and control device described in 6.3.1, with direct oxygen concentration measurement.1.11 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 646元 加购物车

定价： 646元 加购物车