Business services is a general term that describes work that supports a business but does not produce a tangible commodity. Information technology (IT) is an important business service that supports many other business services such as procurement, shipping and finance.
A mass airflow sensor. A mass (air) flow sensor (MAF) is used to find out the mass flowrate of air entering a fuel-injected internal combustion engine. The air mass information is necessary for the engine control unit (ECU) to balance and deliver the correct fuel mass to the engine. Air changes its density as it expands and contracts with temperature and pressure.
And, on engines that do not have a Mass Air Flow (MAF) sensor, the MAP sensor signal is also used by the PCM to calculate engine load -- how hard the engine is working. This is called the speed-density method of calculating engine load for engines without MAF sensors. It is because of this engine load calculation for speed-density engines that the accuracy of the MAP sensor signal is so critical. On OBD-II engines, the MAP sensor signal is also used for EGR diagnosis.