Description: Selectable from two units W/m² and Btu Peak value retention and data retention function. This solar energy tester measures directly use without adjustment. Steadily measure for a long period. Suitable for solar radiation measurement, solar energy research, meteorology, agriculture, physical and optical experiments. Specification: Material: Electronic components Resolution :0.1W/m², 0.1 Btu/(ft²-h) Range error :±10W/m²[±3 Btu/(ft²-h)] or ±5% of the measured value Temperature error :±0.38W/m²/°C[± 0.12bTU /(ft²-h)/°C] when deviating from 25°C Display :4-1/2LCD display Max display value: 19999 Measurement Range:0.1-1999.9 W/m² 0.1-1999.9 Btu/(ft²-h) Wavelength range :340-1100nm Operating temperature and humidity: 0 to 40°C less than 80%RH Storage temperature and humidity: -10 to 50°C less than 70%RH Power:9V Size Chart: Size:132x60x38mm /5.20x2.36x1.50inch Package Includes: 1 Piece Solar Power Meter 1 Piece Package Case 1 Piece User Manual