GB/T 33869-2017 Comparison method of absolute pyrheliometers GB/T33869-2017 |tt||Standard compression package decompression password: www.bzxz.net
This standard specifies the comparison conditions, comparison methods, data processing, comparison results and comparison time intervals of absolute pyrheliometers. This standard is applicable to the comparison of absolute pyrheliometers. 　　

ICS07.060
National Standard of the People's Republic of China
GB/T33869—2017
Comparison method for absolute pyrheliometer
Comparison method for absolute pyrheliometerPublished on 2017-07-12
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of ChinaStandardization Administration of the People's Republic of China
Implementation on 2018-02-01
2 Terms and Definitions
Comparison Conditions
Comparison Method
Data Processing
Comparison Results
Comparison Time Interval
References
GB/T33869—2017
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This standard was drafted in accordance with the rules given in GB/T1.1-2009. This standard was proposed by the China Meteorological Administration.
This standard is under the jurisdiction of the National Technical Committee for Standardization of Meteorological Instruments and Observation Methods (SAC/TC507). GB/T33869—2017
This standard was drafted by: National Meteorological Metrology Station, Yunnan Atmospheric Sounding and Security Center, Jiangsu Radio Science Research Institute Co., Ltd. The main drafters of this standard: Yang Yun, Ding Lei, Quan Jimei, Chong Wei, Lin Bing, Wang Yunkun, Hu Mei, Wang Xin, Zhu Ya, Xu Yigang, Yan Jiajunm
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1 Scope
Comparison method of absolute direct pyrheliometer
GB/T33869—2017
This standard specifies the comparison conditions, comparison method, data processing, comparison results and comparison time interval of absolute direct pyrheliometer. This standard applies to the comparison of absolute direct pyrheliometers. 2 Terms and definitions
The following terms and definitions apply to this document. 2.1
Absolute cavity pyrheliometer absolutecavity pyrheliometer is a direct irradiance measuring instrument with a cavity receiver and self-calibrated using the electrical substitution method. Note: It is divided into active and passive types. 2.2
Compensated pyrheliometer
Compensated pyrheliometer Angstrompyrheliometer is a direct irradiance measuring instrument with two parallel sensing plate receivers and self-calibrated using the electrical substitution method. 2.3
comparison
The process of comparing the values ​​reproduced by the same measuring instruments with the same accuracy level or specified uncertainty range under specified conditions.
3 Comparison conditions
3.1 Environmental conditions
The surroundings are open and there are no obstacles above the instrument sensing surface. 3.1.2
The sky is clear and the direct solar irradiance is not less than 700W·m-2. It is best to measure between 10 and 14 local time. 3.1.3
The air temperature is within the range of 10℃ to 30℃, the relative humidity should not be greater than 80%, and the wind speed should be less than 3m/s. The technical indicators of the standard instrument and supporting equipment shall meet the following requirements: a) Solar radiation measurement standard group: at least 3 or more different types of cavity-type absolute direct pyrheliometers directly traceable to the World Radiation Reference (WRR), with an uncertainty of no more than 0.3%. b) Digital instrument: 0.05 level, resolution should be no more than 1μV. c) Solar tracker: Tracking error should not exceed 0.25°d) Environmental measurement instrument: Technical indicators are shown in Table 1.1
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GB/T33869—2017
Meteorological elements
Measurement range
Resolution
Maximum allowable error
4 Comparison method
4.1 Method overview
Table 1 Technical indicators of environmental measurement instruments
Relative humidity
Under the environmental conditions that meet 3.1, select at least one cavity-type absolute direct pyrheliometer from the solar radiation measurement standard group, and perform synchronous parallel comparison with the absolute direct pyrheliometer to be compared. Use the direct irradiance values ​​obtained by the standard meter and the compared meter to calculate the ratio. 4.2 Specific requirements
4.2.1 Install the standard meter and the compared meter on the solar tracker, and the distance between them should be less than 20m. The digital instrument should be placed in a shaded place outdoors to avoid direct sunlight. Turn on the instrument and preheat for more than 30 minutes as specified in the instrument operation manual. 4.2.2 The standard and the table to be compared should be aimed at the sun at the same time (the light spot should be aimed at the center of the bull's eye), and the instrument self-calibration should be completed according to the instrument manual. 4.2.3 The irradiance values ​​of the standard and the table to be compared should be measured synchronously at the specified time, and the sampling time interval is 1 minute. At the same time, record the temperature, relative humidity and wind speed during the measurement. The timing setting should meet the following requirements:
a) The active cavity type absolute direct pyrheliometer performs closed light measurement and exposure measurement alternately, and the irradiance values ​​of each group of measurements should not be less than 10;
b) The passive cavity type absolute direct pyrheliometer performs exposure measurement continuously, and the irradiance values ​​of each group of measurements should not be less than 20; the left or right receiver of the compensated absolute direct pyrheliometer performs closed light measurement or exposure measurement alternately, and the irradiance values ​​of each group of measurements should not be less than 10.
The measurement series should not be less than 25 groups, and the time of all data acquisition systems should be synchronized. 4.2.4
4.2.5 During the comparison, the operator should approach the instrument from the north. 4.3 Meteorological parameter measurement
Meteorological parameters (air temperature, relative humidity and wind speed) are measured by environmental measuring instruments and are 10-minute average values. Data processing
5.1 Irradiance calculation
5.1.1 The active cavity absolute direct pyrheliometer calculates the irradiance value according to formula (1):wwW.bzxz.Net
E=C(U..I.-U..I.)
Where:
Irradiance, unit is watt per square meter (W·m-): (1)
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C—calibration coefficient, unit is per square meter (m=2); GB/T33869—2017
U. - Voltage output value in the light-off state (the average value of the two light-off measurements before and after the exposure state), in volts (V): I
Current output value in the light-off state (the average value of the two light-off measurements before and after the exposure state), in amperes (I); U. - Voltage output value in the exposure state, in volts (V); I.
- Current output value in the exposure state, in amperes (I). 5.1.2 The irradiance of the passive cavity absolute direct pyrheliometer is calculated according to formula (2):
Vhired -Vah.rero U. (
Vh.cal -Vhero R.
Where:
Vehirad
Vth cal
Calibration coefficient, in units of per square meter (m-2): Output value of the thermopile during irradiation, in volts (V): Zero output value of the thermopile, in volts (V): Output value of the thermopile during calibration, in volts (V): Voltage across standard resistor i, in volts (V); standard resistor, in ohms (Q):
Voltage across heater h, in volts (V): Correction factor for error caused by wire heating, in ohms (Q). Compensated absolute direct pyrheliometer
Calculate the irradiance value according to formula (3):
Uleft·Uiight
Where:
Uileft
When the left receiver is irradiated, the The voltage across the standard resistor i, in volts (V); Ui.ight
5.2 Ratio calculation
When the right receiver is irradiated, the voltage across the standard resistor, in volts (V). 5.2.1
Calculate the ratio of the standard table to the compared table according to formula (4): Ebi)
Where:
The ratio of the direct solar irradiance of the i-th group of measurement sequence of the standard table and the compared table; (2)
+(4)
The measured value of the direct solar irradiance of the i-th group of measurement sequence of the standard table, in watts per square meter (W·m-); The measured value of the direct solar irradiance of the i-th group of measurement sequence of the compared table, in watts per square meter (W·m-2). 5.2.2 Calculate the average value of the ratio of the i-th measurement series according to formula (5): BG
Where:
-the average value of the ratio of the j-th measurement series; n
Number of measurements.
+（5）
5.2.3 Calculate the standard deviation of the individual measurement values ​​in each measurement series according to formula (6). When the absolute value of the difference between any individual measurement value Bij and the average value Bc) is greater than 3 times the standard deviation, the individual measurement value should be deleted and BG and s should be recalculated: 1
(B(ai)B)2
Nn-1台
Where:
The standard deviation of the individual measurement values ​​in each measurement series. 5.2.4 Calculate the average value of the ratio of the m groups of measurement series according to formula (7) (retain to four decimal places): 1B(
Where:
—the average value of the ratio of the m groups of measurement series;
measurement series.
Comparison results
After the comparison, a comparison result report shall be issued, which shall at least include the following contents: laboratory name and address;
comparison location (if different from the laboratory address): c)
comparison date;
identification of the technical specification on which the comparison is based, including name and code; description of the traceability and validity of the measurement standards used for the comparison; comparison environmental conditions;
comparison result description (such as comparison data, ratio and standard deviation, etc.); signature of the person issuing the comparison report.
Comparison time interval
7.1 The comparison time interval should be 2 years, and the maximum should not exceed 5 years. 7.2 When replacing important parts, repairs involving measurement performance, or when there is doubt about the performance of the instrument, a comparison should be made in a timely manner. 4
（6）
·（7)
References
GB/T12936—2007 Terminology of Solar Thermal Utilization JJG456—1992 Verification Procedure for Direct Solar Radiation Meters JJF1071—2010
Rules for Writing National Metrology and Calibration Specifications
ISO9060-1990
GB/T33869—2017
Solar Engergy—Specification and classification of instrument for
measuring hemispherical solar and direct solar radiation[5]
World Meteorological Organization. Guide to Meteorological Instruments and Methods of Observation (Seventh edition), No. 8, 2008[6]
World Climate Research Propramme, Baseline Surface Radiation Network (BSRN) operations manual, version 2.1
GB/T33869-2017
People's Republic of China
National Standard
Absolute direct pyrheliometer comparison method
GB/T33869—2017
Published and distributed by China Standards Press
No. 2, Hepingli West Street, Chaoyang District, Beijing (100029) No. 16, Sanlihe North Street, Xicheng District, Beijing (100045) Website spc.net.cn
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Printed by China Biaoyan Publishing House Qinhuangdao Printing Factory Distributed by Xinhua Bookstores in various regions
Format 880×12301/16
Printing Sheet 0.75 Word Count 12,000 Words
First Edition July 2017
First Printing July 2017
Book Number: 155066·1-56332
2Price 16.00 yuan
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