Pour 100 ml of distilled water into a beaker.
Remove the cap from the measuring tip of the TDS meter. Insert the measuring tip of the meter in distilled water. Stir the meter in distilled water to clean the tip effectively.
Remove the meter from the beaker and shake it to remove the distilled water from the tip.
Pour 100 ml of the water to be tested into another beaker.
Insert the TDS meter in the water. Ensure the measuring tip is immersed in water and does not touch the bottom of the beaker.
Turn on the meter by pressing the "On/Off" button. Wait for seven to eight seconds till the readings on the screen become constant.
Note the reading from the screen. This is the TDS of the water sample.