A gas sensing device (100) for sensing ground gas is disclosed, comprising a power source (117, 118) and data processing and memory means (113), which store sampling configuration data and sensed data. The device (100) further comprises sensing means (104, 105, 110) operably interfaced with the power source and the data processing means. The sensing means samples ambient gas adjacent the device according to first sampling configuration data and outputs sensed gas concentration data and sensed gas flow data. The device further comprises a telemetry module (114) operably interfaced with the power source and the data processing means. The telemetry module communicates the sensed data to a remote terminal and receives second sampling configuration data from the remote terminal for updating the first sampling configuration data. The sampling configuration data comprises data representative of a frequency and duration of gas flow measurement, data representative of a frequency and duration of gas concentration meas
