... humic acid , organic matter,salinity, and PH in the soil, fertilizer and plants, and also can store datum ... organic matter, salinity, and PH in the soil, fertilizerand plant2.With the function of time display, can automatically ... checked at any time.4.Print like the test date, number, items, sample contents, variety and so ... ) Direct current: 18V,5W (With tester)The product picture for your reference.