ORP(Oxidation-reduction potential) digital water tester can accurately and quickly check the organic matter in water, which is extremely accurate and reliable, quick response; Hydrogen drinking water: -150mV and -400mV; Normal drinking water:+150-550mV; Freshwater Fish Tank: 230-260mV; Seawater Fish Tank: 350-450mV.Widely used in domestic water, hydrogen-rich bottle, aquaculture, fish tank water quality, marine aquaculture, freshwater aquaculture, flower and plant cultivation, laboratory testing, ecological research and swimming pool, etc.The probe uses high-sensitivity electrodes; The probe is removable to prevent accidental damage, and the plug-in design makes it easy to replace the probe by yourself; IP67 rating, brief Hydrogen test pen immersion. 18 month and lifetime friendly customer service.When the meter is on in the air, the value will be change in normal; When using the test pen, please cover the protective cap in time to avoid the test electrode being exposed to dry air for a long time, which may cause slow or unstable data reading; If the electrode is dry, keep the electrode moist in distilled water; When the data is abnormal, press and hold the "MODE" button and "HOLD" button at the same time for 3 seconds to restore the factory settings.Hydrogen drinking water: -150mV and -400mV; Normal drinking water:+150-550mV; Freshwater Fish Tank: 230-260mV; Seawater Fish Tank: 350-450mV.How to use 3 in 1 H2/ORP/TEMP Meter?1. Remove the protective cap gently;2. Turn the meter on by pressing the "ON/OFF" button;3. Immerse the meter electrode in the test solution (immersion depth can not be over the immersion line);4. Stir gently and wait until the reading stabilized;5. If you need test temp, please press "TEMP/HOLD" button longly to get the reading;6. After finished use, clean the electrode with distilled water. and turn off the meter, and close the protective cap.Tecnical Parameters:H2 measurement range: 0 - 2400ppb (0.001-2.4ppm);Resolution: 1ppb, 0.001ppm;Accuracy: 2%, reliable and quick readings;ORP Measurement Range: -1200-+1200mV;Resolution: 5mV;Accuracy: 10mV;TEMP Measurement Range: 32.18-140F;Resolution: 33.8F;Accuracy: 32.18F;Factory calibrated;Voltage: 4*1.5VMaterial: ABScolour: redPackage Contents:1 x Hydrogen water bottle testerOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.