SR20-D2 Pyranometer

SR20-D2 Pyranometer

Digital Class A pyranometer with Modbus RTU and 4-20 mA output

SR20-D2 is a solar radiation sensor of the highest category in the ISO 9060 classification system: secondary standard. SR20-D2 is designed for the solar PV industry, offering two types of commonly used irradiance outputs: digital via Modbus RTU over RS-485 and analogue 4-20 mA (current loop). These industry standards allow for easy data acquisition, easy read-out and error-free instrument exchange, when using SR20-D2. Individually tested for temperature and directional response, SR20-D2 is the most accurate digital secondary standard pyranometer available.

Best pyranometer for the PV industry

SR20-D2 is the most accurate digital secondary standard pyranometer available. Its benefits:

• Digital output: easy implementation & servicing
• Best-in-class temperature response, < ± 0.4 % (-30 to +50 °C), best  “zero offset a” and best calibration uncertainty
• Test certificates for temperature response and directional response included as required by ISO 9060
• Re-calibration registers fully accessible to users

In order to improve overall measurement accuracy, Hukseflux effectively targeted two major sources of measurement uncertainty: calibration and “zero offset a”.
In addition, SR20-D2 has a negligible temperature response. All are best in class. The temperature response of every individual instrument is tested and corrected onboard by the instrument electronics, using a second degree polynomial. SR20-D2’s low temperature dependence makes it the ideal candidate for use under very cold and very hot conditions.

SR20-D2 pyranometer design

The pyranometer employs a state-of-the-art thermopile sensor with black coated surface, two domes and an anodised aluminium body. The connector, desiccant holder and sun screen fixation are very robust and designed for long term industrial use. SR20-D2 uses a high-end 24-bit A/D converter. All parts are specified for use across SR20-D2’s entire rated operating temperature range. SR20-D2 offers two types of outputs commonly used in the solar PV industry: digital output via Modbus RTU over 2-wire RS-485 and analogue 4-20 mA output (current loop).

Application of this instrument

Suggested use

• PV system performance monitoring
• all networks with regular instrument exchange
• scientific meteorological observations
• reference instrument for comparison
• extreme climates (tropical / polar)

Specifications