1.1 本测试方法涵盖了先前测试方法的集成 E913年 处理垂直轴日射强度计的校准和先前的试验方法 E941型 轴倾斜的日射强度计校准。这两种方法的融合基本上使该方法与ISO 9846相协调。 1.2 本试验方法适用于所有日射强度计，无论采用何种辐射接收器，也适用于水平和倾斜位置的日射强度仪。 1.3 对于世界气象组织（WMO）和ISO 9060定义的所有二级标准日射强度计的校准，以及使用测试方法进行校准转移时用作参考日射强度仪的任何日射强度表，本测试方法均为强制性的 E842型 . 1.4 包括两种类型的校准:I型校准采用自校准- 校准、绝对日射计和II型校准使用二级参考日射计作为参考标准（二级参考日射计由WMO和ISO 9060定义）。 1.5 参考日射强度计的校准可通过一种方法进行，该方法利用了高度方位或赤道跟踪安装，其中在遮光盘测试期间，辐射计辐射接收器的轴与太阳对准。 1.6 确定校准因子（校准函数）对变量参数的依赖性称为表征。本方法未具体涵盖日射强度计的特性。 1.7 该测试方法仅适用于使用太阳作为光源的校准程序。 1.8 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建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.9 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《国际标准、指南和建议制定原则决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 4.1 日射强度计是一种辐射计，设计用于测量太阳辐射和天空辐射的总和，其比例取决于太阳高度、大气条件和云量。当向赤道倾斜β角时，日射强度计仅测量落在辐射接收器平面内的半球辐射。 4.2 该试验方法是校准参考日射强度计的唯一实用方法。虽然所使用的太阳跟踪器、遮光盘、瞬时读数数量和电子显示设备因实验室而异，但该方法提供了所需的最低可接受条件、程序和技术。 4.3 虽然理论上，倾角（β）的选择是无限的，但实际上，在接近现场使用的天顶角的倾斜角度范围内，可以获得令人满意的精度。 4.4 在倾斜位置执行的倾斜校准与特定倾斜位置相关，在该位置不需要倾斜校正。然而，可能需要倾斜校正以将校准与其他方向（包括垂直轴）相关。 注1: WMO高质量日射强度计的倾斜误差通常小于0.5 %. 倾斜误差是由于1000 W·m时从0°到90°的倾斜变化导致的0°倾斜（水平）时响应度的百分比偏差 2. 3. . 4.5 通过与参考绝对日射计进行比较，可实现世界辐射基准（WRR）校准的可追溯性，该参考绝对日辐射计本身可通过以下方式之一追溯到WRR: 4.5.1 1980年以来在瑞士达沃斯举行的国际日射比（IPC）之一（IPC IV）。参见参考文献 ( 3- 7. ) . 4.5.2 在美国、加拿大或墨西哥举行的任何类似的比对，并被世界气象组织批准为绝对空腔日射仪的区域比对。 4.5.3 与参加过IPC或WMO的任何绝对腔式太阳热仪进行相互比较- 过去五年内批准的相互比较，发现其在±0.4以内 % 所有参与其中的绝对日射计的平均值。 4.6 本测试方法中采用的校准方法假设，所获得值的精度与一年中的时间无关，受测试仪器温度补偿电路的限制（忽略余弦误差）。

1.1 This test method covers an integration of previous Test Method E913 dealing with the calibration of pyranometers with axis vertical and previous Test Method E941 on calibration of pyranometers with axis tilted. This amalgamation of the two methods essentially harmonizes the methodology with ISO 9846. 1.2 This test method is applicable to all pyranometers regardless of the radiation receptor employed, and is applicable to pyranometers in horizontal as well as tilted positions. 1.3 This test method is mandatory for the calibration of all secondary standard pyranometers as defined by the World Meteorological Organization (WMO) and ISO 9060, and for any pyranometer used as a reference pyranometer in the transfer of calibration using Test Method E842 . 1.4 Two types of calibrations are covered: Type I calibrations employ a self-calibrating, absolute pyrheliometer, and Type II calibrations employ a secondary reference pyrheliometer as the reference standard (secondary reference pyrheliometers are defined by WMO and ISO 9060). 1.5 Calibrations of reference pyranometers may be performed by a method that makes use of either an altazimuth or equatorial tracking mount in which the axis of the radiometer's radiation receptor is aligned with the sun during the shading disk test. 1.6 The determination of the dependence of the calibration factor (calibration function) on variable parameters is called characterization. The characterization of pyranometers is not specifically covered by this method. 1.7 This test method is applicable only to calibration procedures using the sun as the light source. 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. ====== Significance And Use ====== 4.1 The pyranometer is a radiometer designed to measure the sum of directly solar radiation and sky radiation in such proportions as solar altitude, atmospheric conditions and cloud cover may produce. When tilted to the equator, by an angle β, pyranometers measure only hemispherical radiation falling in the plane of the radiation receptor. 4.2 This test method represents the only practical means for calibration of a reference pyranometer. While the sun-trackers, the shading disk, the number of instantaneous readings, and the electronic display equipment used will vary from laboratory to laboratory, the method provides for the minimum acceptable conditions, procedures and techniques required. 4.3 While, in theory, the choice of tilt angle (β) is unlimited, in practice, satisfactory precision is achieved over a range of tilt angles close to the zenith angles used in the field. 4.4 The at-tilt calibration as performed in the tilted position relates to a specific tilted position and in this position requires no tilt correction. However, a tilt correction may be required to relate the calibration to other orientations, including axis vertical. Note 1: WMO High Quality pyranometers generally exhibit tilt errors of less than 0.5 %. Tilt error is the percentage deviation from the responsivity at 0° tilt (horizontal) due to change in tilt from 0° to 90° at 1000 W·m 2 3 . 4.5 Traceability of calibrations to the World Radiometric Reference (WRR) is achieved through comparison to a reference absolute pyrheliometer that is itself traceable to the WRR through one of the following: 4.5.1 One of the International Pyrheliometric Comparisons (IPC) held in Davos, Switzerland since 1980 (IPC IV). See Refs ( 3- 7 ) . 4.5.2 Any like intercomparison held in the United States, Canada or Mexico and sanctioned by the World Meteorological Organization as a Regional Intercomparison of Absolute Cavity Pyrheliometers. 4.5.3 Intercomparison with any absolute cavity pyrheliometer that has participated in either and IPC or a WMO-sanctioned intercomparison within the past five years and which was found to be within ±0.4 % of the mean of all absolute pyrheliometers participating therein. 4.6 The calibration method employed in this test method assumes that the accuracy of the values obtained are independent of time of year, with the constraints imposed and by the test instrument's temperature compensation circuit (neglecting cosine errors).