Calculated power plant pH with conductivity measurements

Mettler Toledo have released a white paper discussing ’the pH and CO2 determination based on power plant conductivity’ The correlation between conductivity of ammonia and pH has been used for decades to compare cycle chemistry measurements. With a decrease in personnel overseeing power plant cycle chemistry today, there is a greater reliance on on-line instrumentation. Calculated pH can be more accurate and reliable than high purity pH measured with a conventional glass electrode.

The calculated pH approach can be highly useful because conductivity sensors require far less maintenance than pH sensors. By combining specific conductivity measurement with cation conductivity, a solutions pH can be calculated. For normal plant operations, this is more accurate than using a conventional glass electrode. If degassed cation conductivity is also measured, Dissolved Carbon Dioxide can be determined.

This simplicity also extends to installation, start-up, calibration and maintenance, and each one of these areas can represent significant savings in time and production downtime.