Reduces dust, raindrops and snow on the dome.
Overview
Ventilation of radiometers improves the reliability and accuracy of the measurement by reducing dust, raindrops and dew on the dome. With thermopile-based instruments ventilation stabilizes the temperature of the radiometer and suppresses thermal offsets. The integrated heater can be used to disperse precipitation and melt frost, or even melt snow and ice in cold climates.
Kipp & Zonen's CVF4 is a low power, low maintenance ventilation unit. The only part that needs maintenance is the removable air inlet filter, which should be checked at regular intervals and cleaned or replaced when necessary.
The flow that the CVF4 creates is unique. At the top of the pyranometer dome the flow is very high and it swirls to improve the air distribution over the dome. The position of the heaters and the new cover material ensures that only half the heating power is needed to melt frost and snow compared to older ventilation units.
CVF4 replaces the successful and widely used CVF3 ventilation unit.
Benefits and Features
- Improves stability of measurements
- Easy to install
- Pulse output to monitor performance
Images
Specifications
- Power supply: 12 VDC, 0.9 A (with 5.5 W Heater)
- Operational temperature range: -40 to +70 °C
- Ventilation power: 5 W Continuously
- Tacho output: 5V, 2 pulses per revolution
Compatibility
Pyranometers
| CMP3 | CMP6 | CMP11 | CMP21 | CMP22 | SMP3 | SMP11 | CGR4 | CUV5 |
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Mounting
The L27084 mounting stand is used to fasten the CVF4 to a mast or crossarm. The CVF4 is not compatible with the CM245 mounting stand.
Power Considerations
The 10.5 W ventilator and heater current drain is approximately 900 mA at 12 Vdc, with the 5.5 W heater current drain is approximately 460 mA at 12 Vdc. The ventilator draws an additional 5 W of power at 12 Vdc. These power requirements are large compared to most Campbell Scientific products. Because of this, the CVF4 should be powered via the CVP2.