The maintenance-free microprocessor-controlled on-wall sensor AERASGARD® AFTM-CO2 – W with automatic and manual calibration is used for detecting the overall room climate. It measures CO2 within a range of 0…2000 ppm or 0…5000 ppm, air quality (VOC) in one of three sensitivity levels that can be selected LOW / MEDIUM (default) / HIGH, temperature within a range of –35…+80 °C as well as relative ambient humidity of 0…100 % r.H. The measured values are converted into standard signals of 0 -10 V or 4…20 mA (selectable via DIP switches). As an option, the measured values can be shown continuously in the illuminated display.
The relative humidity (% r.H.) quotient of water vapour partial pressure divided by the saturation vapour pressure at the respective gas temperature. A digital, long-term stable sensor used as measuring element for relative air humidity and temperature guarantees exact measurement results.
The CO2 content of the air is measured using an optical NDIR sensor (non-dispersive infra-red technology). The detection range of the sensors is calibrated for standard applications such as monitoring residential rooms and conference rooms. Room ventilation on an as-needed basis, improved well-being and customer benefit, increased comfort as well as reduced operating costs through energy conservation are just some of the benefits of employing the AERASGARD® CO2 sensor.
The explanations above demonstrate that there are applications for CO2 measurements, for VOC measurem ents, but from our perspective, above all, for a combination of both measurands. The crucial factor in this respect is that both of these measurands are not convertible into each other and derivations to or from one another cannot be made. An NDIR CO2 measuring instrument measures selectively and cannot detect any VOC; a VOC mixed gas sensor cannot recognize CO2 molecules.