Loading...
This document specifies calibration methods for a pyranometer using a pyrheliometer as a reference instrument. Three methods are specified in this document.
a)Â Â Â Â Â Â Alternating sun and shade method. This method uses a shading disc to alternately shade and unshade a pyranometer to compare with the tracking pyrheliometer. The test pyranometer can be horizontal, on a fixed tilt or tracking alongside the pyrheliometer.
b)Â Â Â Â Â Â Continuous sun and shade method. In this method, a shaded calibrated reference pyranometer is used in addition to the reference pyrheliometer. The test pyranometer can be horizontal, on a fixed tilt or tracking alongside the reference pyrheliometer, but the reference pyranometer must be mounted in the same plane as the test pyranometer (most often on the horizontal).
c)Â Â Â Â Â Â Â Collimation tube method. In this method, the test pyranometer is mounted on a solar tracker and is equipped with a collimation tube designed to allow the test pyranometer to have the same geometric view as the reference pyrheliometer for a direct comparison of the two instruments.
The methods in this document are applicable for calibration of all pyranometers provided that a proper uncertainty evaluation is performed. Unlike spectrally flat pyranometers, non-spectrally flat pyranometers have a sensitivity that strongly depends on the solar spectrum. Therefore, the calibration result can be valid under a more limited range of conditions.
The result of a calibration is the instrument sensitivity accompanied by an uncertainty. This document includes suggestions for uncertainty evaluation.
| SDO | ISO: International Organization for Standardization |
| Document Number | ISO 9846 |
| Publication Date | Jan. 1, 2025 |
| Language | en - English |
| Page Count | 52 |
| Revision Level | |
| Supercedes | |
| Committee | ISO/TC 180/SC 1 |
Failed to load document history.
| Publish Date | Document Id | Type | View |
|---|