FCX-TR1000: Zirconia oxygen transmitter for process control applications below 1000 ppm
Pewatron has developed an oxygen transmitter that can be easily mounted in process chambers and process installations. The ease of mounting, together with an industrial standard output signal, make the transmitter a preferred solution for process control of oxygen levels in ppm or in % concentration levels. The latest development in the product family is the FCX-TR1000 0…1000 ppm transmitter that allow reliable measurements of oxygen in the very low ppm oxygen level.
The FCX-TR1000 0…1000 ppm transmitter is a fully integrated solution with a low-noise amplification circuit that translates the µA signal from the sensor into a 4…20 mA standard output signal. The transmitter has a high-precision heater controller built-in for an accurate control of the sensor heater voltage and current. The accuracy of the transmitter follows the accuracy of the sensor element itself. Dependent on the exact application, the signal resolution is determined by the sensor element or the amplification circuit and can be as low as +/-1 ppm. The 4-pole connector on the transmitter can easily be connected to a central power supply and the 4…20 mA output signal can easily be fed into a central PLC unit or a display.
Controlled atmosphere applications are growing in importance. Two examples are oxygen control in high purity PSA nitrogen generators (> 3N) and oxygen control in additive manufacturing of highly reactive metal 3D structures (for instance Titanium). In both cases, the process is running continuously or for many hours or even days. Therefore, the reliability and accuracy of the oxygen sensors during the process time is very important, as they are used as quality monitoring parameter. The FCX-TR1000 ppm transmitter is very well suited for both applications, because of the rugged design and the superior performance of the amperometric zirconia sensor. Although the basic sensor element is very hot (~450°C) the transmitter casing remains cold and maximum 10°C higher than the surrounding temperature in the application. The transmitter has a small valve integrated in the construction. This valve can be opened and closed dependent on the application. The obvious advantage of the valve is the possibility to evacuate fast small pockets of the dead volumes in front of the sensor. The sensor can also be delivered with a sinter cap, which is a good option for controlling the flow in front of the sensor in case of large gas flow fluctuations.
