Yokogawa Electric Corporation has developed the ZR802S explosion-proof converter and has released it as part of its Oprex Analyzers lineup in all markets.
The ZR802S converter supports the IECEx, FM, Atex, CSA, China Ex, Korea Ex, India Ex, and Taiwan Ex explosion-proof standards. It is intended for use with the ZR22S explosion-proof zirconia oxygen detector, an existing Yokogawa product with a highly durable zirconia sensor that is highly dust resistant and easy to install and replace. Together, the ZR802S converter and the ZR22S detector comprise a complete oxygen analyzer system.
Up to now, assessment of sensor deterioration by checking the sensor resistance value has normally been carried out whenever maintenance personnel went on site to perform calibration. As this work is usually performed on a scheduled basis at intervals of a month or more, it has not always been possible to spot problems in time, leading to sudden sensor breakdowns and decreased uptime. With its self-assessment function, the ZR802S converter is able to regularly measure the resistance value of the sensor in the ZR22S detector and send this data over a wired connection to the plant’s control system. Once an operator receives notification of a higher resistance value, which is an indication of deterioration in the sensor, maintenance personnel can take immediate action to correct the problem and prevent an instrument failure, thereby sustaining plant uptime.
The ZR802S converter can log up to 40 days of measurements, alarm on/off history, and sensor resistance trend graphs, among other data. As well as being able to directly display logs on the LCD screen, it is also possible to export the data using an SD card. In the event of a fault, it can determine whether it is due to the analyzer system or the distributed control system (DCS) by looking into differences with the data from the host device. This helps reduce maintenance time and the downtime required to find a solution.