The determination of dissolved silicic acid (ortho-silicate) in the watersteam cycle is of great importance for the operation and plant safety in power plants. In addition to the determination of ortho-silicate in the live steam in order to avoid deposits or crystallisation inside the turbine, it is possible to detect an aperture in the anion filter or mixed bed exchanger.

The Digox 602 silica has been further developed and is in accordance with the physical-chemical measuring method of the new VGB guidelines S-006 for the quantitative detection of dissolved silicic acid. A photometric procedure with a detection limit of 3 ppb is used which is ideally suited for the determination of silicic acid in ultra pure power plant water. For determining the measured values, the Lambert-Beer´s law applies in combination with an additional calibration and calculation for the non-linear range in higher concentrations.

Technical features:
•Very low reagent consumption, one reagent set (approx. 3 liters) lasts for 8 weeks at maximum measurement frequency
•Automatic re-calibration, adjustable measuring interval
•Individually selectable sequence and measuring frequency for each channel. Time frame can be adjusted from a continuous measurement up to a measuring interval of 96 hours
•Real blank value determination of chemicals when determining the zero point
•Highly accurate temperature control of the sample
•Galvanically separated signal outputs
•Pressure regulator and easy-to-clean prefilter per channel
•Built-in sequencer for up to 6 sample channels
•Additional connection for the measurement of a laboratory sample