The original portable digital nitrate detector for fruits and vegetables. With just one click GREENTEST 1 can tell you the nitrate level of your fruit, vegetables and whether it is safe to eat. Technical specifications Nitrate measuring range: 0 9999 mg/kg; Measuring time: 3 seconds. Measurement error margin: < 10%; Power source: Li-ion battery. Battery capacity: 720 mh; Additional USB power source. USB charging current: 310 mA; Power Voltage Range: 5V; Use time up to 20 hours**; D openings: 122 52 14 mm; Weight 85g. TFT color screen resolution: 320 240;Operating temperature: 0 +60 . NOTE:*Increasing the number of observations leads to more accurate results.**Usage time determined for default device settings and 720 mAh battery capacity.