Engineers at Fiat have developed a novel concept for a mass air flowmeter to improve control over engine air/fuel ratios. Such control accuracy is important in optimizing engine performance under all operating and environmental conditions. The flowmeter consists of a duct with a circular section containing two piezoelectric microphones located at fixed points along its axis. When these devices are excited by a voltage pulse they emit ultrasonic energy whose maximum amplitude corresponds with their natural resonance (about 300kHz). As soon as the transmission is completed, both devices begin to work as receivers. The time elapsed between the reception of the sound which propagates in the direction of air flow and that which propagates in the opposite direction is closely tied to the air velocity.

Media Info

  • Pagination: p. 59-62
  • Serial:
    • Automotive Engineering
    • Volume: 85
    • Issue Number: 10
    • Publisher: Society of Automotive Engineers (SAE)
    • ISSN: 0098-2571

Subject/Index Terms

Filing Info

  • Accession Number: 00173963
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Jun 14 1978 12:00AM