The Triton D09 is designed for the continuous measurement of trace levels of dissolved oxygen in aqueous systems. The primary application of the Triton D09 is in the monitoring of boiler feedwater. Oxygen should only be present in trace quantities, excessive concentrations of oxygen can result in corrosion damage to the components of the Steam Cycle. Boiler feed water is thermally and chemically degassed to achieve oxygen-free water. This state must be maintained throughout the Steam Cycle.
Using periodic grab samples to measure the ppb oxygen concentration introduces the risk of significant sampling errors. The Triton D09 will continuously measure the ppb level of dissolved oxygen directly in the process eliminating grab sampling errors and providing highly reliable information.
The Triton D09 is a three electrode amperometric sensor, a gold cathode, a current-less silver-silver bromide reference electrode and a current carrying counter electrode . Oxygen molecules diffuse through the membrane and are reduced to hydroxide ions (OH-) at the cathode. Silver is oxidized to silver ions (Ag+) at the anode. A current flows due to the electron release at the cathode and the electron reception at the anode. Under constant conditions, this current is proportional to the oxygen content of the medium.
The sensor's electronics include a closed control loop that adjusts the oxygen specific working potential at the gold cathode. The potential of the working electrode versus the reference electrode is continuously optimized depending on the measured current value. This function calculates an optimum polarization voltage from the instantaneous sensor current and controls it. This leads to an effective minimization of the oxygen independent zero current. The advantages are a better signal resolution and a linearity of the calibration function even with very low oxygen concentrations.
The Triton D09 is a digital sensor, like the Triton D08, all of the signal conditioning, calibration and diagnostic functions are performed inside the sensor. The Triton D08 Analyzer is compatible with both the Triton D08 and D09 sensor. The Triton D09 flow assembly has been specially designed for use with the Triton D09 trace oxygen sensor. It is particularly suitable for processes where there is a minimal dissolved oxygen concentration, e.g., monitoring boiler feed water in power plants.
Installation of the flow cell is easy, using the clip style holder. Simply screw the holder into the wall or onto a panel and connect input and output sample lines to the 6mm tube fittings. This design allows easy removal of the Triton D09 sensor from the flow cell for air calibration. The orientation of the inlet and outlet sample lines automatically purges air from the flow cell when the sensor is returned to service. The measurement chamber is optimized for fast response and all wetted parts are 316L stainless steel.