A well deserved reputation for ruggedness, longevity and accuracy hallmark the TBX557 series industrial hot-tap retractable pH / redox sensors. The sensors are easily applied to most industrial measurement needs. They are renowned for their ability to outperform conventional sensors in the industries' toughest process applications. Solid-state Next Step™ reference technology is the foundation for all TB(X)5 Series electrodes. The totally solid inner reference chamber is charged with potassium chloride (KCl). This non-liquid reference all but eliminates poisoning, plugging and pumping problems that plague conventional liquid, slurry and gel designs.