Abstract: Disclosed is a pyranometer with a housing, a sensor in the housing, an inner window and an outer dome-shaped window both overlying the sensor. An air inlet duct and an air outlet duct extend in the housing and end in a space confined by the outer window for passing air through the space, from the inlet duct to the outlet duct. The housing is substantially closed such that no outside air flows are allowed into the housing and includes a ventilator, the inlet duct being in fluid communication with a high pressure side of the ventilator, the outlet duct being in fluid communication with a low pressure side of the ventilator. The air blown into the space below the outer window is heated by the ventilator power and optionally by and added electrical heater.

Abstract: Disclosed is a pyranometer with a housing, a sensor in the housing, an inner window and an outer dome-shaped window both overlying the sensor. An air inlet duct and an air outlet duct extend in the housing and end in a space confined by the outer window for passing air through the space, from the inlet duct to the outlet duct. The housing is substantially closed such that no outside air flows are allowed into the housing and includes a ventilator, the inlet duct being in fluid communication with a high pressure side of the ventilator, the outlet duct being in fluid communication with a low pressure side of the ventilator. The air blown into the space below the outer window is heated by the ventilator power and optionally by and added electrical heater.

Abstract: A measuring device for a heat exchanger includes a heat exchanger pressure pipe having a pipe wall with a circumference, and an indentation extending over and deforming a portion of the circumference. At least one thermocouple is disposed eccentrically in the portion of the circumference deformed by the indentation. Filling material fills the indentation. A method for producing a measuring device in a pressure pipe of a heat exchanger, a method for monitoring an operating state of a heat exchanger having a pressure pipe, a heat exchanger, and a method for measuring a heat flux, are also provided. The size of the indentation can be decreased for a given size of the thermocouple due to the eccentric configuration of the thermocouple, so that the heat flux is obstructed to a comparatively small degree by the pipe wall while local overheating of the pipe wall is prevented.