Long description: Solar radiation measurements are more stable when the sensor dome stays clean and the sensor temperature remains uniform. HD9906.51 ventilates compatible pyranometers, pyrgeometers and radiometers to reduce type 'A' offset caused by dome cooling and to help prevent dew and frost on optical parts.
For harsh weather, the heating function can be used to remove snow or ice from the sensor dome. Because heating may increase type 'A' offset, it is intended for use only for the time needed to clear snow or ice. The unit is suitable for outdoor use in any weather condition and operates from -30...+70 °C at 0...100 %RH.
Installation is practical in the field. A built-in levelling device supports accurate horizontal positioning, and the unit is supplied with a 5 m cable with free wires. It works with LPPYRA02 and LPPYRA10 pyranometers, LPPIRG01 pyrgeometers, and LPPHOT02, LPUVA02 and LPUVB02 radiometers.
The fan maintains more uniform sensor temperature and directs airflow from bottom to top when polarity is connected correctly.
The heater operates from 12 Vdc ±10% / 7 W and is used only when needed to clear snow or ice from the dome.
The unit supports selected pyranometers, pyrgeometers, photometers and UVA or UVB radiometers listed in the source.
Separate wire pairs are provided for fan power supply and heater power supply, with a yellow/green cable shield.
The sensor is fixed to the base with two supplied screws, and the cable is routed through the groove on the edge of the base.
The fan filter should be checked periodically and replaced when dirty or clogged.
