Photo: How an electronic, colorimetric carbon monoxide detector works. An LED shines through a colored chemical detector onto a photocell. When carbon monoxide is present, the detector changes color, the beam is interrupted, and the photocell no longer picks up light. This triggers the circuit, which sounds the alarm. CO2 monitors, in turn, can be utilized to assess the risk of transmission in a given environment, Huffman said, including situations in which people are either not wearing masks or doing so improperly. As a general rule of thumb, when CO2 levels go up, so does the risk of contracting COVID-19. “After time it builds up, no matter how far you Carbon dioxide, known as CO2, is a naturally occurring gas in the atmosphere. Made up of one carbon atom and two oxygen atoms, carbon dioxide plays a critical role in the environment, the climate, and even your body. Carbon dioxide is one of the main ingredients for photosynthesis, the process by which plants produce their own food from Most incorporate one of the following carbon monoxide detection mechanisms: a biomimetic sensor, electrochemical sensor, or a metal oxide semiconductor. Here’s how each works: Biomimetic sensor: A special gel turns a different color when it comes in contact with carbon monoxide. The shift in color causes the CO alarm to go off. Thermal Conductivity Detector. The TCD is a universal, nondestructive, concentration-sensitive detector that responds to the difference in thermal conductivity of the carrier gas and the carrier gas containing sample. It is generally used to detect permanent gases, light hydrocarbons, and compounds that respond poorly to the FID. kpUOv.