Both TDS and PH digital tester have ATC function, measurement data will not be affected by water temperature, regardless of water TDS or PH testing. The TDS pencil meter and PH pencil meter have the function of automatic shutdown to save battery useful. The and the are easy to use, just press 'ON / OFF' to open and use it, and I just need to press 'ON / OFF' to close it. 5 seconds to get the PH or PPM data, know the water quality accurately. The pen pen can also be used separately when you need it. The digital TDS meter has a measuring range of 0-9990ppm and an accuracy of / -2%, the has a measurement range of 0 to 14.00h, accuracy of 0.01 and resolution of 0.01 TDS tester and pH tester have small size and reduced weight like pens, easy to carry and convenient for you to carry in your pocket when you go out., Weight: 0.35714886444 Pounds, Manufacturer: Rtxbvg