The measurement process for many physical variables is based on its conversion to frequency. Frequency Domain Sensors (FDS) are able to accomplish this task. If a physical parameter is converted to frequency, it can achieve a faster and more accurate measurement. Embedded in automobiles, robotic systems, aerospace crafts, and many other modern devices, FDS are increasing the quality of the measurement while they still needing better frequency measurement and registration methods. Many frequency measurement techniques have been proposed , most of them are based on the counting of the number of complete cycles that exists during a fixed time interval, the time is determined by the counterâs time base. This technique can be named as the classical method. Other techniques are based on reciprocal counting and continuous time stamping. Another technique is one based on frequency measurement by pulse coincidence principle.
Last date updated on July, 2014