A system for monitoring a compressed gas stream, the system comprising: a monitoring device comprising a plurality of sensors (142, 144, 146), each configured to sense a value of a condition of the compressed gas stream, and a first wireless communication device configured to wirelessly transmit data relating to the sensed condition values; and a receiving device comprising a second wireless communication device configured to receive the data transmitted by the first wireless communication device, characterized in that the system further comprises: a first user interface module configured to provide a first user command and a second user command; a first memory storage device configured to store a first range for each of the sensed conditions, and configured to modify one of the first ranges in response to the first user command; a first display device configured to receive and display one or more sensed condition values, and to change the displayed condition value in response to the second user command; a first criteria evaluation module configured to receive the sensed condition values, to compare each of the sensed condition values to the first range of the condition, and to provide a first warning signal in response to the comparing; and a first warning indicator configured to provide a visual or audible warning in response to the first warning signal; wherein each of the first user interface module, the first memory storage device, the first criteria evaluation module, and the first display device is included in one of the monitoring device and the receiving device. a monitoring device comprising a plurality of sensors (142, 144, 146), each configured to sense a value of a condition of the compressed gas stream, and a first wireless communication device configured to wirelessly transmit data relating to the sensed condition values; and a receiving device comprising a second wireless communication device configured to receive the data transmitted by the first wireless communication device, characterized in that the system further comprises: a first user interface module configured to provide a first user command and a second user command; a first memory storage device configured to store a first range for each of the sensed conditions, and configured to modify one of the first ranges in response to the first user command; a first display device configured to receive and display one or more sensed condition values, and to change the displayed condition value in response to the second user command; a first criteria evaluation module configured to receive the sensed condition values, to compare each of the sensed condition values to the first range of the condition, and to provide a first warning signal in response to the comparing; and a first warning indicator configured to provide a visual or audible warning in response to the first warning signal; a first user interface module configured to provide a first user command and a second user command; a first memory storage device configured to store a first range for each of the sensed conditions, and configured to modify one of the first ranges in response to the first user command; a first display device configured to receive and display one or more sensed condition values, and to change the displayed condition value in response to the second user command; a first criteria evaluation module configured to receive the sensed condition values, to compare each of the sensed condition values to the first range of the condition, and to provide a first warning signal in response to the comparing; and a first warning indicator configured to provide a visual or audible warning in response to the first warning signal; wherein each of the first user interface module, the first memory storage device, the first criteria evaluation module, and the first display device is included in one of the monitoring device and the receiving device.