定价： 515元 / 折扣价： 438 元 加购物车

4.1 Ionizing environments will affect the performance of optical fibers/cables being used to transmit spectroscopic information from a remote location. Determination of the type and magnitude of the spectral variations or interferences produced by the ionizing radiation in the fiber, or both, is necessary for evaluating the performance of an optical fiber sensor system.4.2 The results of the test can be utilized as a selection criteria for optical fibers used in optical fiber Raman spectroscopic sensor systems.NOTE 1: The attenuation of optical fibers generally increases when they are exposed to ionizing radiation. This is due primarily to the trapping of radiolytic electrons and holes at defect sites in the optical materials, that is, the formation of color centers. The depopulation of these color centers by thermal or optical (photobleaching) processes, or both, causes recovery, usually resulting in a decrease in radiationinduced attenuation. Recovery of the attenuation after irradiation depends on many variables, including the temperature of the test sample, the composition of the sample, the spectrum and type of radiation employed, the total dose applied to the test sample, the light level used to measure the attenuation, and the operating spectrum. Under some continuous conditions, recovery is never complete.1.1 This guide covers the method for measuring the real time, in situ radiation-induced alterations to the Raman spectral signal transmitted by a multimode, step index, silica optical fiber. This guide specifically addresses steady-state ionizing radiation (that is, alpha, beta, gamma, protons, etc.) with appropriate changes in dosimetry, and shielding considerations, depending upon the irradiation source.1.2 The test procedure given in this guide is not intended to test the other optical and non-optical components of an optical fiber-based Raman sensor system, but may be modified to test other components in a continuous irradiation environment.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 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.1.5 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： 590元 / 折扣价： 502 元 加购物车

定价： 515元 / 折扣价： 438 元 加购物车

定价： 956元 / 折扣价： 813 元

1 Scope 1.1 This Standard specifies construction and testing of mine power feeder cables normally used for power distribution in stationary or semi-stationary applications that are covered by CAN/CSA-M421 and the Canadian Electrical Code, Part I. Th

定价： 910元 / 折扣价： 774 元

定价： 590元 / 折扣价： 502 元 加购物车

This specification covers bare modified concentric-lay-stranded conductors made from round copper wires, either uncoated or coated with tin, lead, or lead alloy for general use in insulated electrical cables. These conductors shall be constructed with a central core consisting of not more than seven wires, surrounded by one or more layers of helically laid wires. For the purposes of this specification, conductors are classified as Class B modified, class C modified, and Class D modified. The conductors shall meet the prescribed construction requirements such as number of wires and diameter. Welds and brazes may be made in rods or in wires prior to final drawing. Welds and brazes may be made in the finished individual wires composing the conductor, but shall not be closer together than prescribed distance. Tests for the electrical properties of wires composing conductors made from soft or annealed copper wire, bare or coated, shall be made before stranding. Tests for the physical properties of these materials may be made upon the wires before stranding or upon wires removed from the complete stranded conductor.1.1 This specification covers bare modified concentric-lay-stranded conductors made from round copper wires, either uncoated or coated with tin, lead, or lead alloy for general use in insulated electrical cables. These conductors shall be constructed with a central core consisting of not more than seven wires, surrounded by one or more layers of helically laid wires.1.2 For the purposes of this specification, conductors are classified as follows (Explanatory Note 1 and Note 2):1.2.1 Class B Modified—Conductors to be insulated with various materials such as rubber, paper, and crosslink polyethylene.1.2.2 Class C Modified and Class D Modified—Conductors where greater flexibility is required than is provided by Class B Modified conductors.1.3 The values stated in inch-pound or SI units are to be regarded separately as standard. Each system shall be used independently of the other. Combining the values from the two systems may result in non- conformance with the specification. For conductor sizes designated by AWG or kcmil sizes, the requirements in SI units are numerically converted from the corresponding requirements in inch-pound units. For conductor sizes designated by AWG or kcmil, the requirements in SI units have been numerically converted from corresponding values stated or derived in inch-pound units. For conductor sizes designated by SI units only, the requirements are stated or derived in SI units.1.3.1 For density, resistivity and temperature, the values stated in SI units are to be regarded as standard.NOTE 1: The significant differences in this specification from Specification B8 are as follows: (1) The central core is permitted to contain up to seven wires drawn into the assembly with an infinite length of lay while Specification B8 permits only one, and (2) The construction is applicable only to stranded assemblies of 19 or more wires.1.4 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： 590元 / 折扣价： 502 元 加购物车

5.1 This vertical flame test provides information regarding the flammability performance of electrical insulating materials.5.2 This test method is used to assess the vertical flame test performance of electrical insulation materials used in wires or cables in Test Methods D2633 and D3032 (Test A), as well as in Specifications D2219 and D2220.5.3 In this test method, the test 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. The results are therefore valid only for the fire-test exposure conditions described in this procedure.1.1 This is a fire-test-response standard.1.2 This fire test method is applicable to electrical insulation materials used for wires or cables. The materials are tested as plastic specimens on their own or installed on the wires or cables.1.3 The ignition source is a gas burner fueled by methane or natural gas.1.4 Use the values stated in SI units in referee decisions; see IEEE/ASTM SI-10. The values given in parentheses after SI units are provided for information only and are not considered standard.1.5 This standard is used to measure and describe 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.1.6 Fire testing is inherently hazardous. Adequate safeguards for personnel and property shall be employed in conducting these tests.1.7 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.1.8 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： 590元 / 折扣价： 502 元 加购物车

定价： 843元 / 折扣价： 717 元 加购物车

定价： 843元 / 折扣价： 717 元 加购物车

定价： 843元 / 折扣价： 717 元 加购物车