The series of JUMO Wtrans wireless temperature measuring systems now contains a transmitter with ATEX approval and with a high temperature-resistant electronics module, that can be used up to a temperature of 125°C. Transmitters with ATEX approval can be put directly into a potentially explosive atmosphere. The receiver is mounted outside the actual EX zone, making installations with protective barriers and supply isolators unnecessary. This transmitter can be located in Zone 0, right up to the process connection. It is also possible to operate the entire instrument in Zone 1, making it possible to regard a hazardous EX area as being completely disconnected from the “outside world”.