Digital second class pyranometer - alternative for PV reference cell

SR05 series is the most affordable range of pyranometers meeting ISO 9060 requirements. These sensors are ideal for general solar radiation measurements and popular for monitoring PV systems. Model SR05-D1A3–PV is made as a perfect alternative to PV reference cells. It offers the same Modbus interface as the most common PV reference cell model for easy compatibility. Relative to PV reference cells, SR05-D1A3-PV has the advantage of higher stability, independence of the PV cell type or anti-reflection coating, and better availability and price of recalibration.

  • Higher stability than PV reference cells
  • Independent of PV cell type
  • Affordable calibration
  • Register structure and content identical to most common reference cells for easy exchangeability
  • Easy implementation and servicing
  • Easy mounting and levelling
  • Pricing: affordable second class pyranometers


SR05-D1A3-PV Design

SR05 pyranometSR05 pyranometer series seen from aboveers employ a thermopile sensor with black coated surface, one dome and an anodized aluminum body with visible bubble level. Optionally the sensor can be delivered with a unique ball levelling mechanism and tube mount or dedicated mounting fixture, for easy installation. SR05-D1A3-PV has an industry standard digital output: Modbus RTU over half-duplex RS-485, that allows multiple sensors to be installed on a single network. In addition, SR05-D1A3-PV has analogue 0-1 V output.

SR05, The Preferred Solution for Commercial Scale PV Systems

SR05-D1A3-PV with different mounting optionsSR05 series is an economical range of ISO 9060 second class pyranometers for measurement of solar radiation received by a plane surface, in W/m² , from a 180 ° field of view angle. SR05 is perfect for predicting generated power and monitoring the overall efficiency of PV power plants. Different mounting options are available, allowing SR05 to be mounted in virtually any situation. The combination of easy installation and its low cost makes SR05 the preferred solution for commercial scale PV systems.

Comparison to Silicon PV Reference Cells

Model SR05-D1A3-PV has a digital output that is identical to the most commonly used photovoltaic reference cell with Modbus over RS-485 output. This allows for easy installation in existing PV monitoring systems, without the need to make major modifications to data logging software, instrument libraries and infrastructure.

Compared to silicon reference cells, pyranometers offer several advantages such as a perfect (cosine) directional response and a flat spectral response over a wide range. Pyranometers therefore measure the maximum available resource and are suitable to act as a reference for all types (for example amorphous, crystalline or thin-film) of photovoltaic cells both with and without anti-reflection coating. See also our Application note pyranometers versus PV reference cells. Moreover, since the working principle of a pyranometer is different from a solar cell, the pyranometer offers a truly independent measurement of the irradiance.

SR05 pyranometer series

Compliant with IEC 61724-1, Class C

IEC 61724-1: Photovoltaic System Performance Monitoring – Guidelines for Measurement, Data Exchange and Analysis – suggests to use pyranometers for PV monitoring; SR05 complies with IEC 61724-1 class C system requirements.

Sensor Manager Software

Hukseflux Sensor Manager software

For communication between a PC and SR05-D1A3-PV(‘s), the Hukseflux Sensor Manager software can be used. It is available for download on our website. The software allows the user to quickly configure SR05-D1A3-PV Modbus address and serial communication settings (baud rate, parity and stopbits) and to plot and export data. Also, the digital outputs may be viewed for sensor diagnostics

Suggested Use

  • General solar radiation measurements
  • (agro-)meteorological networks
  • PV power plant monitoring

Areas of Application

  • Solar energy / PV system performance monitoring


  • PMF02
  • Sensor Manager
  • CMF01



hemispherical solar radiation

ISO 9060:2018 classification

class C (second class)

IEC 61724-1:2017 compliance

class C


PV monitoring commercial and utility scale, PV monitoring small sized




0-1 V
Modbus RS-485

Calibration uncertainty

<1.8% (k=2)

Calibration traceability

to WRR

Spectral range (wavelength)

285 to 3000 ×10⁻³ m

Rated operating temp range

-40 to +80 °C

Standard cable length

3 m

Rated operating voltage

5 to 30 VDC


ball leveling, optionally with tube mount

Digital output


Communication protocol

Modbus over 2-wire RS-485

Transmission mode


Baud rates

1200, 2400, 9600, 19200, 38400 and 115200


IMT-Solar Si-RS485TC-T-MB; other cells upon request

Analogue output


Voltage output

0 to 1 V cable lengths: 10, 20 m

Version order codes

SR05-D1A3-PV, SR05-D1A3-PV-BL, SR05-D1A3-PV-TMBL


• Cable lengths: 10, 20 m
• Extension cable with connector pair: 10, 20 m
• With ball levelling (-BL)
• With ball levelling and tube mount  (for tube diameters 25 – 40 mm, -TMBL)
• PMF01 mounting fixture for Plane of Array installation
• Compatibility: SR05-D1A3-PV’s Modbus interface is exchangeable with IMT-Solar Si- RS485TC-T-MB PV reference cell’s interface. Other reference cells upon request.


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