Minimize DO Sensor Maintenance Case Study
This case study explains how EDP Group, which operates Energia Pecem – one of Brazil's largest power plants, needed to greatly minimize DO sensor maintenance within the plant. Water chemists at the plant rely on a wide range of analytical sensors to monitor water quality at all times to minimize corrosive or depositing conditions. One of the most critical parameters being measured is dissolved oxygen (DO). EDP had been using polarographic sensors for DO monitoring, and although measurements from these DO probes was reliable, maintenance to keep them operating dependably was excessive. Once a week, maintenance engineers needed to remove each DO sensor, clean it internally, change the electrolyte, calibrate it, and polarize it. This process took over eight hours, during which time the measurement point for each probe was unavailable. In addition to the maintenance burden, the sensors were analog and susceptible to cable interference that would reduce measurement reliability.
In order to resolve the issue, EDP worked with METTLER TOLEDO to find a better analytical solution that would provide the measurement accuracy that the plant chemists required. The Pure Water Optical DO Sensor with Intelligent Sensor Management (ISM) provided the low maintenance, digital signal, and diagnostics that satisfied all of Energia Pecem's requirements. A test system comprised of a Pure Water Optical DO Sensor and M800 transmitter was installed on one of the plant's water panels, with minimal adaption to the existing structure. After a 30-day evaluation, the benefits were clear: reliable measurements, most importantly, as well as no maintenance required during the test period.
Since installation a year ago, Energia Pecem could further evaluate the system. ISM's predictive diagnostics kept them informed of the oDO sensor's condition. The Dynamic Lifetime Indicator showed when the sensor's oxygen-sensing element, the OptoCap, would need exchanging. The transmitter displayed the number of days left until the cap would need replacing. In the year following installation, no replacement was needed – and no maintenance was required.
Read more about the Pure Water Optical DO Sensor, ISM and the M800 transmitter by visiting:
- Pure Water Optical DO Sensor – High-performance oDO sensor that has been designed specifically for demanding power plant and microelectronics applications.
- M800 Transmitter – Multi-parameter transmitter that, when paired with the Pure Water Optical DO Sensor, ensures a dissolved oxygen monitoring system of unequalled performance and reliability.
- Intelligent Sensor Management (ISM) – Digital sensor technology that ensures predictable maintenance, simple sensor handling, and efficient production.