Cable solutions are not necessary in smaller plants and in logistics operations where intermediate materials are stored, there may be no instrumentation and thus no feedback on storage levels. Cable solutions may also be discounted for economic reasons because there are obstacles between the control system and the plant itself. Level measurements, which are currently taken manually, can easily be replaced by a radio control method. Here there is no necessity for real-time transfer, and if a level value cannot be transmitted for a short period, it will not interfere with the operation of the plant.
There are also new possibilities in the sphere of environmental monitoring. One example is corrosion measurement using CorrTran® MV from Pepperl+Fuchs. Corrosion measurement is applied to critical areas of a vessel or pipeline. These positions are often extremely difficult to access or far away from the control system. A wireless CorrTran® MV can be optimally installed without an extensive wiring. Here, the security of the transmission is not a critical application, and since corrosion is an extremely slow process, it is not time-critical.
Another new possibility is the monitoring of operating elements that are actuated in the field, such as ball valves. Previously the status of such valves had been visually monitored by patrol checks carried out by employees. However, through wireless transmission of the ball valve position, its status is available at all times in the control room. Cyclic patrol checks and confirmation of the correct position of valves before plant start-up are no longer necessary. This not only saves a few Euros in labor costs, plant start-up is faster and production rates are higher. Of course the same applies to all the other manually checked status parameters, such as pressure and temperature.
Radio transmission can also be used for quality assurance and the optimization of important process parameters. These parameters, typically less critical to the process control, are often only temporarily monitored, in the event of the isolation of faults, for example, and in temporary plant installations with low volume requirements and frequent product changeovers.
In these applications, wireless technology improves the information on plant status, material flow and process sequence. It provides a basis for sequence and process optimization, asset management and decisions relating to preventive maintenance. Wireless technology improves the economy of process plants.