Description
The RT1 instrument is a high quality radiometer designed for measuring solar irradiance on a plane surface (radiant flux, W/m²), which results from the sum of the direct solar radiation and the diffuse sky radiation above the instrument. The RT1 features internal digital signal processing and interfaces optimised for industrial data acquisition and control systems. The RT1 includes a smart interface that features RS485 Modbus data communication for connection to programmable logic controllers (PLC’s), inverters, digital control equipment and the latest generation of data loggers.
RS485 Modbus Data Output
The RT1 features a smart interface that outputs digital data directly to PLCs, inverters, or SCADA systems using the Modbus RTU protocol. The default communication settings are 19200 baud, 8 data bits, even parity, and 1 stop bit.
The RS485 data string provides the following primary information:
- Solar Irradiance: Real-time radiant flux in W/m².
- Back-Panel Temperature: Precise temperature from the integrated 10k NTC sensor.
- System Status: Internal health checks and error flags to ensure data reliability/li>
- Calibration Factors: Built-in temperature correction to maintain accuracy across varying weather conditions
With no moving parts and a specialized diffuser designed to shed dust and dirt, the RT1 is a low-maintenance, “fit-and-forget” solution for rooftop PV monitoring. It is calibrated with traceability to the World Radiometric Reference (WRR), ensuring that its measurements meet high international standards for solar energy monitoring.
Specifications
| Irradiance Range | 0 to 200Wm² |
| Spectral Range | 400 to 1100 nm |
| PV Panel Temperature | -40 to +100°C, ±1°C |
| Communication | Modbus RTU over 2-wire RS485 |
| Power Requirement | 5-30 VDC (12V Recommend) |
| Power Consumption | Maximum 60mW |
| IP Class | IP67 (with plugs attached) |
| Dimensions (Unpacked) | approx 81 x 77.5 x 60.5 mm |
| Operating Temperature | -40 to +80°C |



