Before installing any type of purifier in a domestic environment, every company operating in the sector carries out simple measurements with special instruments to determine certain values of the water output. These measurements concern the fixed residue which is carried out with the TDS, the electrical conductivity with the conductivity meter and the pH which is carried out with the pH meter. The same operations can be carried out at any time after installation of the device, they give instant results and are sufficient to verify the quality of the water. If you wish to carry out more in-depth studies, which are not required by law, biological, organic and physical-chemical analyses of the purified water can be carried out by a laboratory and subject to payment. It should be noted that companies are not required to carry out any kind of chemical analysis before and/or after the installation of their products. However, companies are obliged by law to carry out periodic maintenance on the purifier and therefore to replace worn parts that are saturated with solids and contaminants.