TDS stick for testing the salt concentration

For controlling a R.O. unit you can easily measure the electrical conductivity or the concentration of Total Dissolved Solids = TDS. If you have this value of the feed water and the pure water you can calculate the . If the rejection is high (more the 95%) the pure water has a good water quality, if not you must check the pre filter and/or the membrane.

For a measurement you take the TDS stick from its bag. After removing the protective cap you can dip the stick directly into the water. Press on "on/off" button and the measured value in ppm appears. If you can not dip the stick at the same time into the water and read it out, it is possible to press during immersing the "hold" key. The measured value is frozen and can be read out outside of water, too.