| 摘要 |
The invention relates to a pyranometer (1) with a housing (2), a sensor (5) in said housing, an inner window (6) and an outer dome-shaped window (7) both overlying the sensor (5). An air inlet duct (21) and an air outlet duct (17) extend in the housing and end in a space confined by the outer window (7) for passing air through said space, from the inlet duct to the outlet duct. The invention is characterized in that the housing is substantially closed such that no outside air flows are allowed into the housing (2) and comprises a ventilator (10), the inlet duct (21) being in fluid communication with a high pressure side of the ventilator (10), the outlet duct (17) being in fluid communication with a low pressure side of the ventilator (10). The air blown into the space below the outer window (7) is heated by the ventilator power and optionally by and added electrical heater. |
