The hotwire probes are designed for the usage in comination with the hotwire bridges eCTA, aCTA and eCCT.They work well for dynamic flow velocity measurements in air. The calibrated velocity range goes up to 50m/s. Higher velocities are possible. Due to the measurement principle, the probes suit especially for low flow velocities. The probes can be used in other gases as well, but therefore a special calibration is needed. It has to be mentioned, that particles in the flow field can destroy the wire. Also a pollution can change the characteristic line of the probe and leads to wrong measurement values.