Valmet Filtrate Residual Measurement

In chlorine dioxide stages, it is important to measure the total chlorine including chlorite. The Valmet Filtrate Residual Measurement (Valmet Polarox5 F) sensor can measure chlorite shortly after chemical addition. This ensures that sufficient bleaching chemical is available for the whole reaction time without adding excessive amounts. Final pulp quality can be achieved without compromising environmental conditions and wasting chemicals.


Continuous pH result provides important information for the process management as the reactions of chlorine dioxide and chlorite are pH dependant. The integrated optional pH measurement in Valmet Polarox5 F allows tighter pH control for optimal process conditions.


  • Enhanced measurement performance thanks to well managed sample conditions in the measurement chamber
  • Measurement chamber with magnetic stirrer designed to be able to provide fast measurement response due to small sample volumes
  • Total active Cl2 measurement in wide pH swings enabled by special measurement electrodes
  • Reliability and long term availability of pH measurement ensured by integration in the filtrate sample flow
  • Easy and safe installation and maintenance