EGE flow sensors for explosive environments permit the space-saving flow measurement on site and the comfortable setting of the limit value using separate amplifier, e.g. within a control cabinet. The measurement takes place without mechanically moving parts using a thermal measuring element. The current flow state is displayed at the amplifier using LEDs. The devices are used wherever a safe, robust and low-maintenance monitoring of flow values is required. The measuring sensors of the product series ST 400 Ex; STS; STEX have ATEX approval and may, dependent on their design, be used in Gas-Ex areas requiring equipment for EPL Ga or EPL Ga/Gb. In the Dust-Ex area their use is permitted up to EPLDa.