Process Instruments (UK) Ltd. (Pi) products

Pi’s DAFSense coagulation and dosing controller is an integrated controller that accepts multiple inputs from multiple sensors including inlet solids pH, and flow. From these measured parameters, the DAFSense outputs a flow proportional coagulation control signal that can go to a coagulant and flocculant dosing pump.

Pi’s Charge Analyzer is used for determining charge demand at the wet end of a paper machine, accurately measuring colloidal and ionic charge using the streaming current principle (electrokinetic charge), which is comparable to zeta potential. Charge demand is determined with polyelectrolyte titration to the isoelectric point, either manually or by use of an automatic titrator. Pi’s ChargeSense Charge Analyzer is intuitive, flexible and gives great repeatable charge demand determinations time after time. Using a larger sample than its competitors ChargeSense gives extremely precise and reproducible results.

What’s the best way to control coagulation on a water treatment plant? The answer is that it depends on the water, the type of plant and the coagulant used. Pi’s CoagSense automatic coagulation controller is an integrated controller that accepts multiple inputs from appropriate parameters including pH, flow, temperature, UV254, turbidity and streaming current. From these measured parameters, the CoagSense outputs a flow proportional coagulation control signal that can go to a site SCADA or direct to control a coagulant dosing pump.

Why is conductivity measurement important in water treatment? The conductivity of water is extremely important when treating drinking water or industrial water because it gives an indication of the amount of dissolved material within that water. Process Instruments supplies a range of high-quality low-cost conductivity sensors to cover the full range from deionized water all the way up to highly saturated brines. Coupled with Pi’s controllers these sensors provide excellent and cost-effective process control in all industries and applications.

How is chlorine dioxide in water measured online? Online, continuous Chlorine Dioxide Analyzers and Controllers make up the DioSense range, which utilizes the best and most recent chlorine dioxide sensors available worldwide.

How do you continuously measure high concentrations of Chlorine Dioxide solution online? Measuring a high level of ClO₂ in solution is extremely difficult and has been traditionally done with expensive at-line optical instruments. The DioSense HR (0-3500 ppm) is an optical sensor measuring the absorbance of light at a particular frequency which is proportional to the amount of chlorine dioxide in the solution.

How is fluoride dosed into drinking water? In some parts of the world (including the USA but not Canada), the local health authorities have determined that adding fluoride to drinking water provides sufficient health benefits (reduction in tooth decay) to justify the cost. In these plants the fluoride is added in solution to the water so that the final concentration is approximately 1 mg/L. This is done by using flow proportional dosing. In addition the final concentration is often monitored to validate the flow proportional dosing. The FluoriSense is perfect for this application. By simplifying the sample preparation process (by removing the TISAB used by other analyzers) Pi are able to reduce the cost significantly whilst still providing the accuracy required to validate flow proportional dosing. Please note that by removing the TISAB common in other analyzers the accuracy will be reduced.

Free Chlorine and Total Chlorine analyzers and controllers measure the free residual chlorine (OCl^– and HOCl), and the total residual chlorine (free chlorine + combined chloramines). The Pi residual chlorine analyzers are amperometric membraned sensors that bring a number of advantages over traditional colorimetric analyzers, in that they are cheaper to own with no reagants and very little maintenance (once per year). They are extremely stable and work almost anywhere you have a need to measure residual chlorine from drinking water, to pools and spas, produce washing, cooling tower disinfection and disinfection in paper and pulp industries.

Measuring the chlorine content of bleach is difficult due to the aggressive nature of the fluid and is currently done by manual titration in a laboratory. The HypoSense allows the user to measure the chlorine content of industrial sodium hypochlorite (industrial bleach) online, continuously. Why is it necessary to measure the chlorine content of bleach online and continuously? Surprisingly the chlorine content in bleach changes more than you might think. It degrades over time and is particularly affected by the level of impurities, the chlorine content when it was manufactured, and the temperature and UV level that it is kept at. Being able to measure the chlorine content online will provide for much better process control in those applications that use bleach as a reactant.