One of the key factors determining the taste of water is its electrical conductivity. Electrical conductivity, as the name of this property of liquid solutions indicates, defines the degree of ease of passing the electrical current through them.
The conductivity measurement unit is called Siemens (S) and the submultiple "μS" is usually used when it comes to measuring it. The instrument that measures electrical conductivity is called conductivity meter. Also, you should be aware that the conductivity measurement is accompanied by the temperature of the solution, as this may alter with the change in temperature.
Water in its pure form of H2O is not electrically conductive. The enrichment of water with numerous elements throughout its interaction with the rest of the natural environment, gives electrically conductive properties. That is, if you measure rain or distilled water you will find that its conductivity is less than 50 μS.
If you have installed a water filtration system, it is advisable to occasionally check the water conductivity levels in order to be 100 μS - 300 μS with a conductivity meter.
To verify the correct operation of the conductivity meter, you can purchase solutions with a specific conductivity. So if there is a deviation between the value seen on the instrument and that on the control solution label, perform the necessary adjustments to the instrument according to the manufacturer's instructions so as these two values to become identical.