Air quality sensor: Aim

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2006 Volvo S80, 2005 Volvo S80, 2004 Volvo S80, 2003 Volvo S80, and 2002 Volvo S80. However, it is still accessible from the selected car via links, so may be relevant.

To offer the customer a passenger compartment which is free of bad odors and pollutants.

General:

By placing an air quality sensor in the air intake it is possible to measure the amounts of polluted air, primarily from motor vehicles. The signal from the air quality sensor is used to exclude the pollutants by using the recirculation (REC) mode. An activated carbon filter is installed in the heater. This filter takes care of the pollutants in the couple of seconds before the recirculation shutter closes and on those occasions when recirculation cannot be used because of misting. The filter and the sensor are interdependent to provide the customer with as clean a passenger compartment as possible. The climate control system is equipped with a button to activate the system.

The filter:

By supplying a particle filter with activated carbon, gases entering the passenger compartment can be absorbed. The focus of exclusion is on the following substances: NO, NO2, HC (benzene, toluene, xylene), CO, ozone.

What can activated carbon absorb?

Cold start: Good absorption of petrol components is usually achieved.

Manure: Ammonia is badly absorbed, however some neutralization can be expected.

Exhausts: Good separation of uncombusted hydrocarbons and "diesel odor" is achieved.

Oil odor: Good.

Water treatment plants: Sulphuric acid cannot be dealt with.

Solvents Good.

Pulp mills: Many odorous substances. Some can be absorbed.

Odors are complicated and are difficult to explain in terms of concentrations and percentages. A filter will reduce odors and minimize strong odor changes and will therefore improve comfort. The car can never be completely odorless. In some cases the odor compounds may seem unexpected because the constituent substance compounds are modified.

Sensor:

The sensor registers NOxCO and HC. These are the most prominent compounds produced by motor vehicles. The sensor registers increases in concentrations, for example when a tunnel is entered or when driving behind a truck. The sensor learns the environment it is in and only reacts to the relevant increase in concentration. One point is that the sensor reacts to CO, a compound which activated charcoal filters cannot handle.