product description:1. [Measurement range]: Conductivity: 09990us/c, TDS: 0-9999ppm, Celsius: 0.180.0C, Fahrenheit: 32.0176.0F2. [Three-in-one test function]: With an advanced three-in-one (TDS, EC, temperature) conductivity pen, the tester can not only detect TDS, but also EC and temperature in water. The ppm meter range is 0-9990 ppm, and the temperature also supports both Celsius and Fahrenheit reading modes.3. [Simple and convenient operation]: Before use, please unplug the electrode protective cover, press the switch key, and put the electrode into the solution to be tested; after the value is stable, press the HOLD key to take out the reading; after the reading is completed , press the switch key, wipe the electrode clean, and put the electrode protective sleeve into it; 4. [Locking function]: Easy to read and record, the instrument will lock the reading; 5 minutes automatic shutdown function, the battery will not run out.