Scope of Application: The TDS meter tester can be used in water purifiers and filters, food (vegetable, fruits) & drink quality monitoring, pools and spas, aquariums, hydroponics etc. Applicable Industries: Water purification detection pen can be applied in water laboratories, CDC, the aquaculture industry, hospitals, swimming pools, household tap water quality testing. Auto-off Function: Water quality testing pen will turns off after 10 minutes of non-use to conserve batteries. Convenience: Pressing TEMP button can shift temperature meter between fahrenheit degree and centigrade degree, and water quality testing pen can saves measurements for convenient reading and recording. High Accuracy: Water purification detection pen adopts high quality chip, titanium alloy probe, which can avoid interference by magnetic field in water, so the data has high accuracy., Manufacturer: Hyuduo