ASTM G167-2015發行信息

標準號ASTM G167-2015

中文名 用直接日射強度表校正日射強度計的標準試驗方法

英文名Standard Test Method for Calibration of a Pyranometer Using a Pyrheliometer

發布日期2015

實施日期

廢止日期無

國際標準分類號07.060

發布單位US-ASTM

ASTM G167-2015適用范圍

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 and health practices and determine the applicability of regulatory limitations prior to use.

1.1本試驗方法涵蓋了先前關于軸垂直日射強度計校準的試驗方法E913和先前關于軸傾斜日射強度計校準的試驗方法E941的集成。這兩種方法的融合基本上使該方法與ISO 9846相協調。

1.2本試驗方法適用于所有日射強度計，無論采用何種輻射受體，也適用于水平和傾斜位置的日射強度計。

1.3本試驗方法對于校準世界氣象組織（WMO）和ISO 9060規定的所有二級標準日射強度計，以及使用試驗方法E842進行校準時用作參考日射強度計的任何日射強度計是強制性的。

1.4包括兩種類型的校準：I型校準采用自校準絕對日射強度計，II型校準采用二次參考日射強度計作為參考標準（二次參考日射強度計由WMO和ISO 9060定義）。

1.5參考日射強度計的校準可通過使用altazimuth或赤道跟蹤裝置的方法進行，其中輻射計輻射受體的軸在遮光盤試驗期間與太陽對齊。

1.6確定校準因子（校準函數）對可變參數的依賴性稱為表征。日射強度計的特性不包括在本方法中。

1.7本試驗方法僅適用于使用太陽作為光源的校準程序。

1.8本標準并非旨在解決與其使用相關的所有安全問題（如有）。本標準的使用者有責任在使用前建立適當的安全和健康實踐，并確定監管限制的適用性。

4.1The 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 x03b2;, pyranometers measure only hemispherical radiation falling in the plane of the radiation receptor.

4.2This 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.

4.3While, in theory, the choice of tilt angle (x03b2;) is unlimited, in practice, satisfactory precision is achieved over a range of tilt angles close to the zenith angles used in the field.

4.4The 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 0.58201;%. Tilt error is the percentage deviation from the responsivity at 0x00b0; tilt (horizontal) due to change in tilt from 0x00b0; to 90x00b0; at 1000 Wx00b7;m23.

4.5Traceability 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:

4.5.1One of the International Pyrheliometric Comparisons (IPC) held in Davos, Switzerland since 1980 (IPC IV). See Refs (3-7).

4.5.2Any 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.

4.5.3Intercomparison 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 x00b1;0.48201;% of the mean of all absolute pyrheliometers participating therein.

4.6The 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).