The use of Electronic nose (e-nose) systems to detect, classify, and in some cases quantify volatile organic compounds (VOCs) and other gases is increasing. An e-nose generally combines one or more chemical sensors to produce a characteristic response for a gas sample. E-nose systems have been investigated for applications including food quality, environmental monitoring, healthcare diagnostics, industrial monitoring, and security. A recent review describes e-noses as systems incorporating sensor arrays with controlled gas flow, data processing, and algorithms that help recognize and classify a distinctive gas mixture [1]. Although sensor technology continues to advance, the performance of an e-nose is dependent on the quality and precision of the chemical gas standards used to develop and evaluate it. Sensors must be calibrated with a known gas composition and concentration before their response is meaningful. Other important factors such as sampling techniques, differences in sensor technologies and materials, data processing, and changes in environmental conditions should be considered during calibration when analyzing e-nose performance.