Digital Photovoltaic Pyranometer – Litemeter Modbus Pro

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Litemeter Modbus PRO is a digital photovoltaic pyranometer (or irradiance sensor) equipped with a monocrystalline silicon cell. Manufacturing and Calibrations are done following the IEC 61215, IEC 60904-2; 60904-4; 60904-10 regulations. The silicon photovoltaic cell is laminated with E.V.A. and a performing anti-reflective glass for photovoltaic modules. It guarantees a fair precision in the measurement of irradiance and provides a measurement of the indicative temperature of the photovoltaic modules next to it. This sensor has a RS485 bus interface, using the well known industry standard protocol Modbus RTU.


All Litemeters are calibrated with our Class A Silicon Reference Cell, itself periodically calibrated by the Dakks accredited ISFH Institute and a HP34410A Multimeter.
Note: the terms irradiance sensor, photovoltaic pyranometer, reference cell and solarimeter are interchangeable. On this site we will use photovoltaic pyranometer. To learn more click here.

Common uses

Litemeter Modbus Pro is ideal for monitoring and managing photovoltaic systems of up to a few hundred kW. It is useful where the monitoring system has RS485 input channels and a high accuracy in performance calculation is not required.

Key features

  • Standard RS485 Modbus RTU protocol output to ensure readings 500m from the datalogger
  • Anti-reflective high performance glass + E.V.A.
  • Two 0-10V outputs: irradiance and cell temperature
  • Aluminum body
  • Mounting bracket for quick installation
  • Resistant to extreme weather
  • IEC EN 61215 par.10,11,12 compliant (product ageing)
  • Calibrations according to IEC 60904
  • Order code that allows you to obtain the most suitable sensor for your climate zone


NAME Litemeter PRO
PRODUCT LM2-485 PRO – monocrystalline silicon cell solar irradiance sensor (solarimeter)
REFERENCE STANDARD IEC 60904-2; 60904-4; 60904-10
OUTPUT Digital
Input range Irradiance: 0 ÷ 1250 W/m2
Spectral range 0.36μm ÷ 1.14μm
Temperature -30 ÷ +85°C (1)
Output signal (digital RS485 standard Modbus RTU) Irradiance 0 ÷ 1250 W/m2 (not temperature compensated)
Output precision Irradiance ±5% (2.5% @S.T.C. (25°C))
Temperature ± 1.0 °C
Response time < 100 milliseconds
Sensor type Digital solarimeter
Supply External 12 ÷ 30V DC
Encapsulation Glass + E.V.A. + Polyester
Cable 3 m shielded 5.7mm diameter cable, conductors 4 x 0,25mm2, UV and high temperature resistant
Connectors Standard M8 4 pin or non present (4+1 pin)
Dimensions 55x98x20.5mm without bracket
IP Protection Grade IP 65
(1): Note: the temperature value is predetermined at project stage and verified at the production stage.


Protection against lightening

Protects irradiance sensors and photovoltaic monitoring equipment from lightening induced overvoltages. Discover Blitz-Wall!


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