Geonica - Model GEO-SR20 - Secondary Standard Pyranometer With Heater

Introduction
GEO-SR20 measures the solar radiation received by a plane surface, in W/m2, from a 180° field of view angle. We recommend to use GEO-SR20 in particular in applications where highest accuracy is necessary. Specifications of GEO-SR20 are very good. Directional response is also tested individually for each sensor and reported.

The "zero-offset A" specification of GEO-SR20 is significantly improved by using dome that is significantly smaller than that of earlier designs. Heating reduces sensitivity to fouling and reduces measurement errors caused by early-morning dew deposition.

Demanding applications
GEO-SR20`s low temperature-dependence makes it an ideal candidate for use under very cold and very hot conditions.
The temperature dependance of every individual instrument is tested and supplied as a second degree polynomial. This information can be used for further reduction of temperature dependance during post-processing. The incorporated heater reduces measurement errors caused by early-morning dew deposition. GEO-SR20`s connector is truly specified for use in its entire rated operating condition.

Uncertainty evaluation
The uncertainty of a measurement (according to the "Guide to Expression of Uncertainty in Measurement" or GUM) with a pyranometer under outdoor conditions depends on many factors. In our manuals you can find guidelines for uncertainty evaluation. We also provide spreadsheets to assist our users in this process. At the same time we wish to stress that measurement accuracy not only depends on instrument properties, but also on measurement conditions. A potentially very accurate instrument like GEO-SR20 will quickly underper-form without a regular schedule of instrument maintenance and cleaning.

NEW: use as sunshine duration sensor
WMO has recently approved of the "pyranometric method" to estimate sunshine duration (rom pyranometer measurements (Chapter 8 of the WMO Guide to Instruments and observation, 2008). This implies that GEO-SR20 may be used, in combination with appropriate software, to estimate sunshine duration (SD measurement included when using data logger)

Suggested use
PV monitoring and testing
Reference instrument for comparison
Extreme climates (arctic / desert)

Standards
Applicable instrument-classification standards are ISO 9060 and WMO-N0.-8; "Guide to Meteorological Instruments and Methods of Observation". The calibration is according to ISO 9847. PV-related standards are ASTM E2848 and IEC 61724.

See also
Alternative sensor: LP02 for lower accuracy measurements
SR12 first class pyranometer for solar energy testing application.
View our complete product range of solar sensors

Options
Addicional cable length in multiples of 5 m (add to the standard 5m)

MORE INFORMATION
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