• Schoolrooms
  • Office buildings
  • Parking garages
  • Washroom ventilation fans
  • Cigarette smoke detectors.

  • True Air Quality Monitor
  • Microprocessor based controller
  • Analog Stepped Output (ASO)
  • 10 bit resolution
  • Able to detect one cigarette in 15 m3
       (530 cu. ft.)room
  • Integral sensitivity adjustment
  • Ability to directly control air handling unit
  • Visual indication of air quality (internal)


  • The AIR-300 is a microprocessor based air quality monitor/controller utilizing a hot wire element sensor based upon the Taguchi principle. This is a full spectrum sensor sensitive to a wide variety of air pollutants such as carbon monoxide, cigarette smoke, benzene, alcohols, hydrogen, hydrocarbons, esters, etc.

    This sensor is better suited to measuring air quality than a sensor which measures only Carbon Dioxide. The AIR-300 yields a true indication of the actual air quality, rather than occupancy. For example, if a person were to smoke a cigarette in a room, the carbon dioxide sensor would be inadequate in detecting this, even though the air quality had significantly degraded. This same set of circumstances holds true for many other contaminants such as Solvents, Fuels, and even Carbon Monoxide, all of which are much more harmful than Carbon Dioxide.

    When measuring Air Quality, it is not so much the type of contaminant that is of concern, but rather the presence of any contaminants. This sensor does not indicate which contaminant is in the air, but indicates the presence and quantity of any contamination.

    The Greystone AIR-300 monitor/controller works by looking at the signal from a full spectrum sensor, automatically compensating for temperature and humidity effects, and judging the degree of pollution. For the unit to perform efficiently it must work as a monitor/controller, i.e. it must be able to act upon level changes. The output is represented as an analog, stepped or relay output with user adjustable settings. This output can be used to directly control an actuator, or be sent back to a Building Automation System (BAS).

    The AIR-300 can be configured to run in auto or manual mode and has an integral sensitivity adjustment to provide the user with the optimum settings to monitor a specified area. There are internal LED indicators to show microprocessor status and also a manual override feature to assist in installing the unit.

    Supply Voltage 20-30 Vac/Vdc
    Supply Current 200mA (max.)(non-isolated)
    Outputs 4-20mA, 0-10Vdc linear for 0-100% pollution. 0-10 Vdc analog stepped and SPDT relay.
    Operating Temperature 0C 40C (32F - 104F)
    Operating Humidity 10% to 90% RH
    Relay Ratings 5A @ 250Vac, 5A @ 30Vdc
    MODEL OUTPUT
    AIR-300-(XX) Stepped Output (0-10Vdc)
    AIR-300-(XX)-A Stepped & Analog Output
    (4-20mA or 0-10Vdc)
    AIR-300-(XX)-A-R Stepped & Relay Output
    AIR-300-(XX)-R Stepped, Analog & Relay Output
    Enclosure (XX) AE - Executive Space
    D - Duct