| Pyrgeometers CGR Series |
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| Pyrgeometers are radiometers for measuring the Far Infrared Radiation (FIR) at wavelengths longer than 4 ?m. The instruments have a silicon window with a solar blind filter coating on the inside to block all short-wave solar radiation. An internal temperature sensor is fitted to enable calculation of the downward longwave radiation. |
CGR 3 pyrgeometer is designed for
good quality measurement in a compact package. The CGR 3 provides a voltage
that is proportional to the incoming FIR. The data represents the radiation
exchange between the instrument and the whole hemisphere because the reference
CGR 3 is calibrated outdoors with respect to a CGR 4, which has a 180
degrees field of view. The CGR 3 has an internal (non replaceable) drying
cartridge and needs little maintenance. |
Kipp & Zonen pyrgeometers are
suitable for permanent outdoor use under all weather conditions. A waterproof
plug and socket is fitted for the signal cable providing ease of installation
and maintenance. A snap-on white sun shield minimizes heating of the pyrgeometer
body. CGR 4 is the best pyrgeometer currently available for the highest quality scientific measurements. The specially designed meniscus dome provides a 180 º field of view with negligible directional response error. A hard-carbon coating on the outside of the dome smoothes the spectral response and provides extra protection to the silicon surface. The excellent thermal stability of the dome construction and coupling to the instrument body eliminates the need for dome temperature measurements or dome shading. CGR 4 can be fitted with the CV 2 Ventilation Unit to further improve its performance. |
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The net long-wave radiation can be calculated using two pyrgeometers, one looking up and one looking down. The CGR 3 is specially designed so that two instruments can be mounted base-to-base and fitted with the optional mounting rod. In this case the temperature of the pyrgeometers is the same and is irrelevant for the net radiation calculation. |
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