Waterline Si05/10/20 and SIO2-05/10/20 (silicica)


The WATERLINE SIO2-01 process photometer is specially developed for the measurement of very low SiO2 concentrations in water. The measurement principle is the photometric determination of dissolved silicic acid after forming of a reduced β-silico-molybdo-acid complex. Main applications for the analyzer are the monitoring of the steam quality and the control of ion exchange plants.

The analyzer consists of a control unit with touchscreen and an analysis unit with measuring chamber, valve, dosing pumps and all required tube connections. The control unit includes a microprocessor which controls the automatic measurement incl. sampling, rinsing, reagent dosing and surveillance of the photodetection systems. The analysis results can be used for the monitoring and control of a supervised process.

  • Automatic measurement incl. self-test and drift compensation
  • 3 different measurement ranges available for Si and for SiO2
  • Easy operation via touchscreen
  • Adjustable limit value and alarm value
  • Programmable analog output (0/4-20 mA), optional with USB port for easy data storage
  • Adjustable break time between two analysis
  • External start/stop of analysis possible
  • No external calibration required
  • External plug connections (IP65) for alarm relay, limit relay, analysis relais, external start/stop, analog output 0/4-20 mA
  • Multi-range power supply (110–230 Volt, 50–60 Hz)
  • Including 2-part polycarbonate wall cabinet
Parameter Silica/Silicic Acid
Description Microprocessor-controlled analyzer for the determination of dissolved silica (Si)/silicic acid (SiO2) in water
Typical Applications Monitoring and control of steam quality in steam-generating plants. Monitoring and control of ion exchange plants
Analysis Method: Photometric determination of the dissolved Si/SiO2 by formation of a reduced ß-molybdosilicic acid complex
Analyzer type Si05/SiO2-05 Si10/SiO2-10 Si20/SiO2-20
Measuring Range 2 – 100 ppb Si
4 – 200 ppb SiO2
2 – 500 ppb Si
4 – 999 ppb SiO2
0,01 – 1,5 ppm Si
0,02 – 3 ppm SiO2
Resolution 1 ppb 1 ppb 0,01 ppm
Accuracy 2 % of end value 3 % of end value
Reproducibility 1 ppb/2 ppb 2 ppb/4 ppb 0,01 ppm/0,02 ppm
Zero-point Stability automatic adjustment
Number of Samples 1
Operating Pressure0,1 - 10 bar
Temperature18 - 30 °C
Sample Volume25 ml per analysis (excluding rinsing)
Sample Conditionclear, with particles < 0.5 g/l ; < 50 µm
Chemical DemandspH 4-8, PO4 3-,NH3 < Si
Drainpressure free into open drain
Number 2
Storage Temp.10 – 30°C
Usage/analysis0,3/1,2 ml
Reagent volume250/500 ml
Suitable forappr. 400 analysis
Cycle (approx.)13 min., incl. rinsing
Sample interval1 – 99 min or external start/stop