Palintest has introduced an improved, easy to use organo-phosphonate test for monitoring OP levels in boiler and cooling water systems. Using a specially developed tablet containing a pH buffer and screened indicator, this new test eliminates the problems of pH adjustment and end-point determination associated with the traditional test, making it more consistent and more accurate.
Low levels of organo-phosphonate compounds are now used worldwide as scale and corrosion inhibitors in boiler and cooling water applications. Monitoring is essential to ensure the treatment is fully effective but, until now, this has been problematic and testing has produced questionable results.
The level of OP in a solution is ascertained by measuring the volume of a thorium nitrate reagent required to complete a reaction with it, using xylenol orange as an indicator. Traditionally, this had to be done under precise pH conditions, often requiring a pH correction procedure first, and the result was difficult to determine due to a poor color change.
The Palintest OP test uses a tablet which combines a pH adjuster and buffer mixture together with a screened xylenol orange indicator. This is simply dissolved in thesample to provide the correct pH conditions for the test. The screened indicator then produces an obvious color change from green to purple only as the decisive drop of thorium nitrate is added. The microburette for adding the thorium nitrate is directly calibrated to OP concentration and provides a readout to a precision of 0.4mg/l.