Thermal Sensors Secondary standard pyranometer with sapphire outer dome SR25 takes solar radiation measurement to the next level. Using a sapphire outer dome, it has negligible zero offsets. SR25 is heated in order to suppress dew and frost deposition, maintaining its measurement accuracy. When heating SR25, the data availability and accuracy are higher than when ventilating traditional pyranometers. SR25 needs very low power. SR25 is an excellent reference for diffuse radiation. Figure 1 SR25 secondary standard pyranometer Introduction SR25 represents the next level in solar radiation measurement. Using a sapphire outer dome, it has negligible zero offsets. SR25 is heated in order to suppress dew and frost deposition, maintaining its high measurement accuracy. When heating SR25, the data availability and accuracy are higher than when ventilating traditional pyranometers. In addition, SR25 needs very low power; it only consumes 1.5 W compared to the usual 10 W for ventilation. The low thermal offsets make SR25 very suitable for measuring diffuse radiation. Patents on the SR25 working principle are pending. SR25 is available with analogue millivolt output. Best data availability Figure 2 frost deposition: clear difference between SR25 (left), versus a non-heated pyranometer without sapphire dome (right) By keeping the SR25 outer dome free of dew and frost with help of the internal heater, data availability is highly increased over traditional pyranometers, whether these are ventilated or not. Copyright by Hukseflux. Version 1813. We reserve the right to change specifications without prior notice Page 1/4. For Hukseflux Thermal Sensors go to www.hukseflux.com or e-mail us: [email protected]

Thermal Sensors Best measurement accuracy SR25 measures the solar radiation received by a plane surface, in W/m2, from a 180o field of view angle. SR25 offers the best measurement accuracy: the specification limits of two major sources of measurement uncertainty have been greatly improved over competing pyranometers: “zero offset a” and temperature response. Figure 5 overview of SR25: (1) cable, (2) fixation of sun screen, (3) glass inner dome, (4) thermal sensor with black coating, (5) sapphire outer dome, (6) sun screen, (7) humidity indicator, (8) desiccant holder, (9) levelling feet, (10)...

Thermal Sensors diffuse measurements all situations where ventilated pyranometers are employed PV system performance monitoring indoor PV testing with solar simulators airborne measurements environments with dew environments with frost sapphire outer dome: negligible zero offsets internal heater: because of dew and frost suppression by heating, better data availability and accuracy than ventilated instruments 1.5 W: very low power consumption test certificates for temperature response and directional response included: all sensors tested individually for ISO 9060 compliance hemispherical solar...

Thermal Sensors SR25 secondary standard pyranometer with sapphire outer dome Nowadays, the best pyranometers are made by Hukseflux Thermal Sensors. This overview of features and benefits of SR25 gives you some of the reasons why! Whatever your application is, Hukseflux offers the highest accuracy in every class at the most attractive price level. Diffuse radiation reference • lowest zero offsets • lowest calibration uncertainty • best temperature dependence Best connector • interchangeable cables • IP67 grade • for industrial use Best sun screen • sealed • corrosion protection of body • no dry-cooking...