A gas measurement system comprising a probe (10), the probe (10) comprises a sensor circuit comprising a thermal dispersion sensor (23) and a reference thermistor (24), the thermal dispersion sensor and the reference thermistor are disposed within a shroud (20), the shroud partially enclosing the thermal dispersion sensor and the reference thermistor such that a gas flow through the shroud is substantially representative of the gas flow through a gas duct, the probe further comprises an elongate member (27) having an aerodynamic form, the shroud is mounted to the elongate member, the elongate member mountable within the gas duct, and a microprocessor for receiving a signal from the thermal dispersion sensor and the reference thermistor, the microprocessor calculating and displaying a gas velocity and gas temperature.