The field of electronic noses and gas sensing has been developing rapidly since the introduction of the silicon based sensors. There are numerous systems that can detect and indicate the level of a specific gas. We introduce here a system that is low power, small and cheap enough to be used in mobile robotic platforms while still being accurate and reliable enough for confident use.
The design is based around a small circuit board mounted in a plastic case with holes to allow the sensors to protrude through the top and allow the natural flow of gas evenly across them. The main control board consists of a microcontroller PCB with surface mount components for low cost and power consumption. The firmware of the device is based on an algorithm that it uses on receiving input from gas sensor .The Testing of the device involves the training of the controller with a number of different target gases to determine the weightings for the algorithm. Accuracy and reliability of the algorithm is validated through testing in a specific gas filled environment.
The Proposed System:
The Gas Sensor Module design involves the use of a lightweight plastic case with holes in the lid to allow the sensors to fit with the top of the sensor exposed to allow the gas to flow easily over them. The main small surface-mount PCB is designed for lower power consumption and this is achieved by the microcontroller switching the analog circuits off during low power sleep mode. The sensor sub board is connected to the main board with a simple quick connect header on each side of the board. The sensors can be mounted directly to this PCB.