Litemeter Modbus Pro – Digital Photovoltaic Pyranometer

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Litemeter Modbus Pro – Digital Photovoltaic Pyranometer

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 high performance 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 irradiance sensor has an 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

  • LM5 – 485 PRO sensor is 25% more precise compared to the previous version LM2 – 485 PRO
  • Standard RS485 Modbus RTU protocol output to ensure readings 500m from the datalogger
  • A high performance anti-reflective 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 LM5-485 PRO – solar irradiance sensor with monocrystalline silicon cell (photovoltaic pyranometer)
REFERENCE STANDARDS IEC 60904-2; 60904-4; 60904-10
OUTPUT Digital
Input range Irradiance: 0 ÷ 1600 W/m2
Spectral range 0.36μm ÷ 1.14μm
Temperature -30 ÷ +85°C (1)
Output signal (digital RS485 standard Modbus RTU) Irradiance 0 ÷ 1600 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 2.5 m or 60cm with M8 4 pin connector
Connectors 4+1 GND loose pins (or M8 4 pin)
Dimensions 98x55x25 mm without fixing bracket
IP code IP 65

(1): Note: the temperature value is predetermined at project stage and verified at the production stage.


  • USB/RS485 interface cable

  • USB/MICRO-USB smartphone adapter

  • Sm configuration for Android smartphone and tablet

    SMCONFIG allows you to configure Litemeter in the field from your Android smartphone. It is no longer necessary to bring irradiance sensor back to the laboratory for configuration.

    The software allows you to:

    • configure Litemeter.
    • make a diagnosis of the basic functions.
    • log irradiance, temperature and wind (Sunmeter Wind only) readings.

    The software is available for free on this page in the downloads area. In addition to the software it is necessary to have a USB / RS485 converter, an adapter cable between microUSB/USB and clamp adapter.
    In the Download area you can find a wiring diagram of our cable that connects Smartphone/Tablet or PC with the irradiance sensor, it takes and transforms the voltage present on the USB (Price on request). Alternatively, it is possible to use other cables with external power supply (9V battery).


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Protection against lightening

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


Drop us a line for free and impartial advice from highly experienced professionals.