[5-in-1 Aquarium Salinity Digital Tester] Measure water temperature in degrees Celsius and degrees Fahrenheit pH(Pondus Hydrogenii) salinity TDS EC,Simultaneous display of 5 parameters, intuitive and convenient.Equipped with battery indicator to control the battery status at any time, No operation, automatic shutdown after 5 minutes, saving energy and electricity.At the same time, there are functions such as automatic range switching and automatic temperature compensation. [Switch Display Interface and Automatic temperature compensation] Can switch the direction of the LCD screen according to preference or use environment,the switching sequence is [General]-[]-[Left Hand]-[General]. tester can automatically compensate for temperature errors based on changes in water temperature,more accurate measurement values. [How to Use] Power on/off:press and release the button 1s to turn on or off the device,automatically turn off after 5 minutes of inactivity. display interface switching:press button for 2s and release to switch between display mode. Function selection:press the button for 5s and release to enter the function selection menu.there are three functions to choose from:pH-CAL,EC-CAL.RESET,stand for pH calibration,EC calibration and restoring to factory. [Widely Used In Life and Aquariums] In aquariummeasure the water temperature measure the pH.The pH value of water is between 6.5 and 9,and the seawater is between 7.5 and 8.5.Test the total solid solubility of water.It is recommended not to exceed 800ppm for fish farming in water(without salt).Test the conductivity of water.The more harmful substances or pollutants in the water,the higher the conductivity,raise marine fish and coral,recommended to range from 1.020 to1.024 ms/cm. Colour:Black Material:Plastic Package Contents: 1 * salinity tester 1 * English manual 1 * usb cable Only 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.