定价： 665元 / 折扣价： 566 元 加购物车

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定价： 1177元 / 折扣价： 1001 元

This specification covers common laboratory or filter funnels, and filling or powder funnels for general laboratory use. The laboratory glass funnels shall be classified into four types which are divided into classes. Type 1 is common laboratory funnel with smooth inner surface which is divided into three classes: Class A with short stem, Class B with long stem, and Class C without stem. Type 2 is laboratory funnel with fluted inner wall. The flutes are small grooves or depressions running upward from the bottom zone of the bowl. This type is divided into Class A and Class B. Type 3 is laboratory funnel with ribbed inner wall. The ribs are small raised protuberances from funnel rim toward the stem. Class A and Class B funnels belong to this type. Type 4 is the last type which is filling or powder funnels. This type has short, wide diameter stem.1.1 This specification covers common laboratory or filter funnels, and filling or powder funnels for general laboratory use.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 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： 515元 / 折扣价： 438 元 加购物车

The current gain of a transistor is basic to its operation and is its single most important parameter. Ionizing radiation, that is, gamma radiation due to a nuclear burst, will degrade the current gain due to lifetime damage in the bulk material. Degradation of gain will be greatest immediately following a burst of ionizing radiation and the gain will rapidly recover to a quasi steady-state value. Defect annealing may continue for weeks but usually the current gain recovery is small or negligible. This method provides a procedure that does not require special-purpose test equipment. This method is suitable for use for specification acceptance, service evaluation, or manufacturing control.1.1 This test method covers the measurement of common-emitter d-c current gain (forward, hFE, or inverted, hFEI) of bipolar transistors, for which the collector-emitter leakage current, ICEO, is less than 10% of the collector current, IC, at which the measurement is to be made, and for which the shunt leakage current in the base circuit is less than 10% of the base current required. 1.2 This test method is suitable for measurement of common-emitter d-c current gain at a single given value of test transistor collector current or over a given range of collector currents (for example, over the range of the transistor to be tested). 1.2.1 The nominal ranges of collector current over which the three test circuits are intended to be used are as follows: 1.2.1.1 Circuit 1, less than 100 [mu]A, 1.2.1.2 Circuit 2, from 100 [mu]A to 100 mA, and 1.2.1.3 Circuit 3, greater than 100 mA. 1.3 This test method incorporates tests to determine if the power dissipated in the transistor is low enough that the temperature of the junction is approximately the same as the ambient temperature. 1.4 The values stated in International System of Units (SI) are to be regarded as standard. No other units of measurement are included in this standard. 1.5 This standard does not purport to address the safety problems, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

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3.1 This collection of test methods is used by pigment producers and paint manufacturers for process control, for product acceptance, and for research and development.1.1 These test methods cover procedures for determining certain properties of pigments. The procedures appear in the following order:Dry Pigments Sections Loss on Ignition and Ash  4Matter Soluble in Water  5Hydrogen Ion Concentration (pH Value)  6Alkalinity or Acidity by Titration 7 and 8Water Content (Distillation Method) 9 and 10 Pigment Pastes in Oil   Water Content (Distillation Method) 9 and 10Pigment Content of Paste in Oil 11Total Volatile Matter in Paste in Oil 121.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 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.1.4 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： 515元 / 折扣价： 438 元 加购物车

1. Scope This part of ISO 6405 establishes the common symbols for use on operator controls and other displays on earth-moving machinery as defined in ISO 6165. These symbols may be used on other types of self-propelled work machines designed to oper

定价： 819元 / 折扣价： 697 元

1 Scope This part of ISO 3767 establishes the common symbols for use on operator controls and other displays on tractors and machinery for agriculture and forestry, and powered lawn and garden equipment as defined in ISO 3339-0 and ISO 5395. The sym

定价： 910元 / 折扣价： 774 元

5.1 Modern offices and other multipurpose buildings commonly have suspended acoustical ceilings installed over room dividing partitions. The test facility prescribed in this test method is useful for providing ceiling attenuation data on the relevant ceiling/partition elements and systems, to ensure that the transmission of sound through the ceiling and plenum space, or through the combination of ceiling, plenum space, and partition systems, provides a suitable degree of acoustical isolation.5.2 This test method is useful for rating and specifying, under standardized conditions, the sound attenuation performance of ceiling materials when mounted in a specified suspension system.5.3 This test method may be useful for selecting a wall-ceiling system for probable compliance with a performance specification for overall sound isolation between rooms. However, the actual field performance may differ significantly, particularly if the field plenum depth is not within the limits specified in this test method or if the plenum space contains large ducts, beams, etc., or both. (See Test Method E336.)5.4 The flexibility inherent in the test facility enables evaluation of the effects of penetrations, induced leakage paths, luminaire, and air diffuser installations and discontinuities in the ceiling suspension system at the partition line, including penetration of the partition into the ceiling plenum. The effect of installing plenum barriers at the partition line may also be investigated.5.5 With the concentration of sound absorbent area offered by a suspended sound absorbent ceiling installed in a room, it is not possible to obtain a good approximation to a diffuse sound field in that room. The plenum dimensions prevent the maintenance of a diffuse sound field above the test specimen. These factors affect the values of the measured ceiling sound attenuation and thus the measurements are not a fundamental property of the ceiling. The test method measures the acoustical properties attainable under the prescribed test conditions, which have been arbitrarily selected. The conditions must be adhered to in every test facility so that the measured results will be consistent. Two methods for obtaining A, the receiving room absorption, are given without preference. One method, known as the steady state method, has been used to obtain an estimate for A in the AMA 1-II-1967 standard. The other method follows the procedures used in Test Methods E90 and C423; justification for the use of this method may be found in reference (1)5. Persons wishing to further investigate the limitations imposed by this test method are advised to read references (2), (3), (4) and (5).5.6 Notwithstanding the above limitations, this type of test method has been used successfully for a number of years to rank order commercial ceiling systems and the test results are commonly used for this purpose.1.1 This test method utilizes a laboratory space so arranged that it simulates a pair of horizontally adjacent small offices or rooms separated by a partition and sharing a common plenum space. The partition either extends to the underside of a common plenum space or penetrates through it. In the prescribed configuration, special design features of the facility ensure that the only significant sound transmission path is by way of the ceiling and the plenum space.1.2 Within the limitations outlined in the significance statement, the primary quantity measured by this test method is the ceiling attenuation of a suspended ceiling installed in a laboratory environment. By accounting for receiving room sound absorption, the normalized ceiling attenuation may be determined.1.3 The test method may also be used to evaluate the attenuation of composite ceiling systems comprised of the ceiling material and other components such as luminaires and ventilating systems.1.4 The field performance of a ceiling system may differ significantly from the results obtained by this test method (see Section 5, , and Test Method E336).1.5 The procedures may also be used to study the additional sound insulation that may be achieved by other attenuation measures. This would include materials used either as plenum barriers or as backing for all or part of the ceiling.1.6 The facility may also be used to study the performance of an integrated system comprising plenum, ceiling, and partition, tested as a single assembly.1.7 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.8 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.1.9 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

Information technology - International string ordering and comparison - Method for comparing character strings and description of the common template tailorable ordering AMENDMENT 2

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This specification covers a group of requirements that are mandatory for castings produced by the investment casting process to meet the metallurgical requirements of the following steel casting specifications. Chemical, heat, and product analyses shall be performed wherein the material shall meet the specified composition limits for carbon, manganese, silicon, phosphorus, sulfur, nickel, chromium, molybdenum, vanadium, tungsten, copper, and aluminum. The specified design and dimensions of the ICI test bar shall be employed only for austenitic alloy castings. The material shall conform to mechanical properties including tension test requirements.1.1 This specification covers a group of requirements that are mandatory for castings produced by the investment casting process to meet the metallurgical requirements of the following steel casting specifications issued by ASTM.ASTM Designation Title of SpecificationA27/A27M Steel Castings, Carbon, for General ApplicationA128/A128M Steel Castings, Austenitic ManganeseA148/A148M Steel Castings, High-Strength, for Structural PurposesA297/A297M Steel Castings, Iron-Chromium and Iron-Chromium-Nickel, Heat-Resistant, for General ApplicationA447/A447M Steel Castings, Chromium-Nickel-Iron Alloy (25-12 Class), for High-Temperature ServiceA494/A494M Castings, Nickel and Nickel AlloyA560/A560M Castings, Chromium-Nickel AlloyA732/A732M Castings, Investment, Carbon and Low-Alloy Steel for General Application, and Cobalt Alloy for High Strength at Elevated TemperaturesA743/A743M Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion-Resistant, for General ApplicationA744/A744M Castings, Iron-Chromium-Nickel, Corrosion Resistant, for Severe ServiceA747/A747M Steel Castings, Stainless, Precipitation HardeningA890/A890M Castings, Iron-Chromium-Nickel-Molybdenum Corrosion-Resistant, Duplex (Austenitic/Ferritic) for General ApplicationA915/A915M Steel Castings, Carbon and Alloy, Chemical Requirements Similar to Standard Wrought GradesA958/A958M Steel Castings, Carbon and Alloy, with Tensile Requirements, Chemical Requirements Similar to Standard Wrought GradesA1002 Castings, Nickel-Aluminum Ordered Alloy1.2 This specification also covers a group of supplementary requirements that may be applied to the above specifications as indicated therein. These are provided for use when additional testing or inspection is desired, and apply only when specified individually by the purchaser in the order.1.3 When investment castings are ordered, the requirements stated in this specification form an integral part of the material specification. In cases of conflict, the requirements of this specification shall take precedence over the individual material specification requirements.1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.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