Portable Digital Pen TDS Meter Filter Measuring Water Quality Purity Tester Water tds Meter Calibrate With Screw 

Product Feature:

Test the quality of various water ensuring you are enjoying the best quality water.

  Calibration 
 

• 1.open the TDS
• 2.Press the "TEMP" button , then The screen will always be

             then can adjust it , when the data is the same with the Correction fluid

• 3.press the 'hold‘ button

• 1* tds-3 meter
• 1*english user manual
• 1*leather bag