Please use this identifier to cite or link to this item:
|Title:||Spontaneous and highly accurate ultrasonic temperature measurement system for air conditioner in automobiles|
|Keywords:||Continuous wave;Microprocessor;Multi-frequency;Phase detector;Ultrasonic measurement|
|Abstract:||This paper presents a microprocessor-based, ultrasonic air temperature sensor system whose output controls temperature adjustment of car air conditioner (AC). Perceived thermal comfort correlates better with temperature of bulk air than temperature measured by conventional in-car temperature sensor. It uses ultrasonic measurement of changes in sound speed in air to determine temperature of bulk air. Changes in sound speed are calculated from phase shift of multi-frequency continuous wave. A 89c51 single-chip microprocessor-based signal generator and phase detector was used to record and calculate phase shift and temperature. Advantages of proposed system are high accuracy, instant detection, wider range and low cost.|
|Appears in Collections:||JSIR Vol.68(01) [January 2009]|
Items in NOPR are protected by copyright, with all rights reserved, unless otherwise indicated.