The monitoring of “Ultra Pure Water” or “High Purity Water” requires the lowest possible detection limits for process analyzers. Resistivity is often around 18 MΩ. Dedicated instruments can detect infinitely small amounts (ppt e.g. parts per trillion) of ions.
The most important parameters in Water/Steam Cycles such as Cation conductivity, dissolved oxygen and pH are available as pre-assembled and factory tested units. Dedicated analyzers for sodium, silica, phosphate and hydrazine are also factory tested and calibrated for immediate operation.
The monitoring of “Purified Water” of “Water for Injection” in the pharmaceutical industry is highly regulated. These instruments comply with the highest pharmacopoeia standards.
Low maintenance and reliability are key requirements for analyzers in potable water plants. Cost of ownership is another big issue.
Public health authorities in some countries regulate the quality of water in public pools and control water treatment tightly. A typical installation comprises several instruments with a common web-server for access via intranet or internet.
A number of treatment products are often added to prevent corrosion, scaling and fouling. Coating of sensors and other effects of these products must be taken into account when selecting analyzers. Discharge monitoring needs special attention because zero measurements must be reliable over time with little maintenance.
Instruments for monitoring the aeration-process, nitrification and de-nitrification; chlorination and de-chlorination; as well as the final discharge into the environment.