2009-Martinez-BPW21 pyranometer.pdfAbstract: This paper presents the design, construction and testing of a new photodiode based pyranometer for the visible spectral range ...(approx. 400 to 750 nm), whose principal characteristics are: accuracy, ease of connection, immunity to noise, remote programming and operation, interior temperature regulation, cosine error minimisation and all this at a very low cost, tens of times lower than that of commercial thermopile-based devices. This new photodiode-based pyranometer overcomes traditional problems in this type of device and offers similar characteristics to those of thermopile-based pyranometers and, therefore, can be used in any installation where reliable measurement of solar irradiance is necessary, especially in those where cost is a deciding factor in the choice of a meter.
2010-Medugu- BPW21- pyranometer.pdfAbstract :There is a problem of availability of sufficient and functional instruments for measuring solar radiation ... in Nigeria due to the high importation costs and maintenance. In order to alleviate this problem, the design, construction and testing of a reliable model pyranometer (RMP001) was done in Mubi, Adamawa State of Nigeria. Detailed instructions were provided for assembly and calibration. Bearing cost, photodiode active-surface and signal-to-noise ratio in mind, the most suitable photodiode for this application was BPW21. The pyranometer was constructed around the photodiode held with a protective plastic case. The CMP3 pyranometer was used as a standard for calibration and comparison. A calibration constant of 5230 ± 0.02 Wm-2 was obtained. The stability of the RMP001 compared favourably with the CMP3 during a day open – sky test giving irradiances of 20.76 and 21.7 Wm-2 for RMP001 and CMP3, respectively, at 5:25 p.m. RMP001 will be used for the collection of authentic irradiance data for comparative evaluation with the theoretical predicted results given by researchers.