TSI Incorporated is excited to announce the expansion of the TSI AirAssure? Indoor Air Quality (IAQ) Monitor product line. The newest addition, the AirAssure? 8144-2, a two-gas model designed to help you understand and manage common indoor air pollutants utilizes low-cost sensor technology to continuously monitor carbon dioxide (CO2), total volatile organic compounds (tVOC), particulate matter (PM), and other indoor air conditions.