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Important features :
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The CNR 4 net radiometer measures the energy balance between incoming short-wave and long-wave Far Infrared (FIR) radiation versus surface-reflected short-wave and outgoing long-wave radiation.
The CNR 4 net radiometer consists of a pyranometer pair, one facing upward, the other facing downward, and a pyrgeometer pair in a similar configuration. The pyranometer pair measures the short-wave radiation and the pyrgeometer pair measures long-wave radiation. The upper long-wave detector of CNR 4 has a meniscus dome. This ensures that water droplets role off easily and improves the field of view to nearly 180°, compared with a 150° for a flat window. All 4 sensors are integrated directly into the instrument body, instead of separate modules mounted onto the housing, although calibrated each individually for optimal accuracy.
Two temperature sensors, a Pt-100 and Thermistor, are integrated for compatibility with every data logger. The temperature sensor is used to provide information to correct the infrared readings for the temperature of the instrument housing. Care has been taken to place the long-wave sensors close to each other and close to the temperature sensors. This assures that the temperatures of the measurement surfaces are the same and accurately known, which improves the quality of the long-wave measurements.
The design is very light in weight and has an integrated sun shield that reduces thermal effects on both long-wave and short-wave measurements. The cables are yellow with waterproof connectors as used with all our new radiometers. The mounting rod can be unscrewed for transport.
An optional ventilation unit with heater is designed as an extension of the sunshield and can be fitted new to the CNR 4 or retro-fitted later. This unit is compact and provides efficient air-flow over the domes and windows to minimize the formation of dew and reduce the frequency of cleaning. The integrated heater can be used to melt frost.
The CNR 4 specifications comply with the WMO classification of good quality.
Specifications
| Sensitivity | 5 - 20 µV/W/m² |
| Spectral range (short wave) | 305 to 2800 nm |
| Spectral range (long wave) | 4500 to 42000 nm |
| Temperature dependence of sensitivity (-10 ºC to +40 ºC) | < 4 % |
| Operating temperature | -40ºC to +80ºC |
| Response time | < 18 s (95 %) |
| Non - linearity | < 1 % |
| Weight | 360 g |
Option : CNF 4 Ventilation Unit
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Important features :
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The Kipp & Zonen CNR 4 net radiometer is produced as the standard instrument or with an integrated ventilation unit and heater.
The CNF 4 ventilation unit can also be bought as a kit for retro-fitting to a CNR 4 that was purchased without it. CNF 4 provides a clean air flow over all four of the CNR 4 radiometer domes and windows and is designed to operate under all weather conditions. The only part that needs maintenance is the air inlet filter, which should be checked at regular intervals and cleaned or replaced when necessary.
The integrated 10 W heating can be switched on by the operator when required. This raises the temperature of the domes and windows slightly above ambient to prevent the formation of dew and frost and to disperse precipitation. The ventilation fan and heater run from 12 VDC and can be operated by the accessory CVP 2 universal AC-DC power adaptor.
Specifications
| Power Input | 12 VDC, 1,3 A (with 10 W heater) |
| Operating Temperature | -40ºC to +70ºC |
| Ventilation fan power | 5 W continuously |
| Heating | 10 W |
| Weight | 500 g |
