Self cleaning cell for selective analysis of oxidising substances, 606
Sensors for oxidising substances (chlorine, chlorine dioxide, chlorites, ozone, peracetic acid, hydrogen peroxide, bromine, iodine, permanganate) in aqueous solutions including special electrodes and peculiar operating features; their selectivity, sensitivity, accuracy and reliability cannot be easily found in other analysers presently available in the market.
The mechanical electrodes de-passivation system allows the use of these cells in all those applications where traditional cells could not work because of the presence of fouling substances that would deposit on the electrodes rapidly making the measure unreliable.
Mod.606 cells have been designed for applications where selective and accurate oxidant analysis is a basic issue because the concentration to be detected is very low, or very high, or because high reliability for long operating periods with no maintenance needs is required. Another typical application of this cell is for oxidising substances measurements in sea water.
These sensors are made of a polycarbonate through flow chamber that houses the measuring electrode, the counter electrode, the reference electrode, the optional temperature sensor for measurement thermo-compensation and the brush for mechanical electrodes depassivation. The electrodes are directly immersed into the sample that flows in the chamber with a constant flow rate, controlled by the cell itself; the electrodes are kept clean and active by the action of the brush.
The polarization voltage impressed across measuring electrode and counter electrode and the proper amplification factor make the cell selective to different oxidising substances. The cell is absolutely free of unwanted effects like corrosion of the electrodes: noises due to these phenomena are so forth completely avoided even in critical applications like sea water measurements, wastewater applications and measures at high concentrations.
The reference electrode can be selected among two versions so that the cell can be used in very harsh applications.
Typical applications of these cells are in drinking water plants, food and beverage industry, bottled waters industry, sea water swimming pools, thermal springs swimming pools, once through cooling systems, recirculating cooling systems, fish breeding and seafood breeding, wastewater treatment plants, paper mills and hospitals.
Materials at contact: PC, PTFE, PVC, Stainless Steel or Hastelloy (instead of SS)
Counterelectrode and Working electrode, C and W: inert material
Reference Electrode, R (with salt bridge): calomel (for the use in harsh conditions) or silver/silver chloride
Operating temperature Limits: 5 to 50°C.
Measuring ranges: 0-2000 ppb, 0-10 ppm, 0-2000 ppm
Power supply: 24 Vac or 110 Vac or 220 Vac, optionally 24 Vdc
Consumption: 3 W
Optionally the brush can be pneumatically actuated. Pneumatic actuator requirements: filtered air, P > 2 bar
Sample flowrate does not affect the measure. It has to be adjusted so to obtain a correct response time and properly representative measure (number of sample renewals per hour) (e.g.20-800 L/h)
Max. salt concentration: no limitation for Cl- concentration
Max.concentration for iron salts Fe(II) and Fe(III): 1 ppm as Fe
Max.allowed sample hardness: 10°f; above this value a frequent electrodes cleaning may be required
Some of the typical use of these selective cells: measure and control of chlorine, chlorine dioxide, chlorites, ozone, peracetic acid, hydrogen peroxide, bromine for the following applications:
dosage of disinfectant in drinking water,
control of disinfection in the in IV range products preparation
determination of chlorine or other oxidizing substance in sea water
analysis of the oxidizing agent (e.g. peracetic acid, chlorine dioxide, chlorine etc.) in fruit and vegetables disinfection and processing
measure of chlorine in swimming pool water
control of on-site hypochlorite generators
disinfection of bottles in bottling machines