Digital Solar Power Meter Data Retention Fast Sampling High Accuracy Sun Light Energy Tester with Compass Item Type: Digital Solar Power Meter Material: ABS Model: LX 107 Power Supply: 6F22 9V battery x 1 800mAh (battery included) Use: Solar radiation measurement, solar energy research, physical optics laboratory, high performance window recognition, meteorological, agricultural and other fields testing Range: 2000W/㎡, 634BTU (ft² x h) Accuracy: Range: ±10W/㎡ or ±5% (whichever is greater) Temperature Coefficient: ±0.38W/㎡/℃ (when deviating from 25℃) Range: BTU/(ft² x h) Or ±5% (whichever is greater) Temperature Coefficient: ±0.12BTU/(ft² x h)/℃ (when deviating from 25℃) Data Retention, Peak Retention, Low Battery Display, Automatic Shutdown: Yes Compass Function: Yes Maximum Display: 1999 Angle Accuracy: Cosine correction <±5% (angle <60 degree Drift: ±2% per year Overload Display: Display OL Sampling Rate: 2.5 times per second Sensor: UV photodiode with filter lens Operating Temperature: 5℃ to 40℃, less than 80% RH Storage Temperature: -10℃ to 60℃, less than 70% RH Screen Size: Approx. 65x35mm/2.6x1.4in