The Velocity Gauge enables the gas flow in the batch chamber to be checked during gas quenching. It allows preventive testing of the quenching system, supports fault analysis in the event of quenching problems and helps to ensure the quality of gas-quenched components. The gauge works according to the physical measuring principle of a Prandtl sensor, which makes it possible to measure the distribution of the flow velocity over the base area of a quenching chamber without great effort. The selected measuring principle and the simple measuring setup ensure that the measurements are reproducible and independent of operating influences. Following the measurement, a protocol with the current measurement data is generated. This data can be compared with the data at the time of delivery of the quenching system.