1.1 本规程包括在305的气体速度范围内测定S型皮托管系数 米/分钟至1524 m/min或5.08 m/s至25.4 m/s（1000 ft/min至5000 ft/min）。该方法适用于隔离的S型皮托管的校准（参见 5.1 )和皮托管叶组件。 1.2 本规程概述了通过在正常工作范围中点附近的单个速度设置下进行校准来获得S型皮托管系数的程序。通过该方法获得的S型皮托管系数通常在±3范围内有效 % 超过正常工作范围。如果需要S型皮托管系数和速度之间更精确的相关性，则采用多速度校准技术( 附件A1 )应该使用。当流量不在管表面的轴上时，本规程为S型皮托管确定的校准系数不适用于现场使用。 1.3 这种做法可用于校准气体速度超过3的热风速计 m/s（10 ft/s）。 1.4 以国际单位制表示的数值应视为标准。括号中给出的值是对英寸磅单位的数学转换，仅供参考，不被视为标准。 1.5 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 S型皮托管( 图1 )通常用于测量工业烟囱和管道中流动气流的速度。 在将S型皮托管用于此目的之前，必须通过对照标准皮托管进行校准来确定其系数 ( 2. ) .

1.1 This practice covers the determination of Type S pitot tube coefficients in the gas velocity range from 305 m/min to 1524 m/min or 5.08 m/s to 25.4 m/s (1000 ft/min to 5000 ft/min). The method applies both to the calibration of isolated Type S pitot tubes (see 5.1 ), and pitobe assemblies. 1.2 This practice outlines procedures for obtaining Type S pitot tube coefficients by calibration at a single-velocity setting near the midpoint of the normal working range. Type S pitot coefficients obtained by this method will generally be valid to within ±3 % over the normal working range. If a more precise correlation between Type S pitot tube coefficient and velocity is desired, multivelocity calibration technique ( Annex A1 ) should be used. The calibration coefficients determined for the Type S pitot tube by this practice do not apply in field use when the flow is nonaxial to the face of the tube. 1.3 This practice may be used for the calibration of thermal anemometers for gas velocities in excess of 3 m/s (10 ft/s). 1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard. 1.5 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. 1.6 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. ====== Significance And Use ====== 5.1 The Type S pitot tube ( Fig. 1 ) is often used to measure the velocity of flowing gas streams in industrial smokestacks and ducts. Before a Type S pitot tube is used for this purpose, its coefficients must be determined by calibration against a standard pitot tube ( 2 ) .