Available Gas Concentration, Sensors, Probes & Connectors0 pages

www.ahlborn.com ri GAS CONCENTRATION IN AIR Why is the Measurement of Room Air Quality So Important? An unsatisfactory room air quality of indoor rooms (e.g. in offices) can easily cause tiredness, poor powers of concentration and even diseases to people. Indicator for the room air quality is the concentration of specific gases in air. The most important ones include: ► Carbon dioxide (CO2) ► Carbon monoxide (CO) ► Oxygen (O) ► Ozone (O3) CO2 Concentration An important criterion for the evaluation of the room air quality is the CO2 concentration. A CO2 concentration, which is too high due to insufficient ventilation, is experienced as stale or stagnant air. The illustration above shows the range of CO2 concentrations that are relevant to a human. CO Concentration CO is produced when carbon is only partially combusted (fuel). CO is very dangerous for humans because it is at the same time highly toxic - and invisible and odorless. Reasons for the production of CO in various combustion processes : ► deficiency of air ► too high excess of air ► too early cooling down of flame Effects of CO in the ambient air on the human body CO concentration Inhalation period and consequences s. e g n a ch al ic ni ch te e a m to igh e e vr er s re e un o o 30 ppm 0.0003% Maximum concentration in the workplace per 8-hour shift (German MAK value) 200 ppm 0.02% Slight headache within 2 to 3 hours 400 ppm 0.04% Headache within 1 to 2 hours, first in the forehead and temples, then spreading to the whole heac 800 ppm 0.08% Dizziness, nausea, and twitching limbs within 45 minutes, unconsciousness within 2 hours 1600 ppm 0.16% Headache, dizziness, nausea within 20 minutes, death within 2 hours 3200 ppm 0.32% Headache, dizziness, nausea within 5 to 10 minutes, death within 30 minutes 6400 ppm 0.64% Headache and dizziness within 1 to 2 minutes, death within 10 to 15 minutes 12800 ppm 1.28% Death within 1 to 3 minutes Applications ► measurement, control, and warning system in garages, ► monitoring of room air quality with respect to maximum permissible workplace concentration (MAK value) ► monitoring of outside air or of protected air systems in domestic and large public shelters 16.02 5