| 摘要 |
An ultrasonic measuring apparatus (Fig. 2) and method (Fig. 5) to accurately determine the depth of an overlaying backfat (14-20) on an animal (8) without incurring any damage to the animal. The apparatus employs a reverse time analysis approach in which a pulse generator (28) sends a preselected ultrasonic input signal by way of a piezoelectric transducer (16) through the outer skin (12) and successively through each one of the animal's fat layer interfaces (15, 17, 20) to a preselected distance within the loin portion (22) of the animal. This reverse time approach then analyzes the resulting echo signal produced by the input signal sequentially in a direction from this loin portion toward the outer fat layers (14, 16, 18). The first strong signal within a specified range, which depends on the species, breed, age or weight of the animal to be measured, is taken as the bottom-most fat/loin transition. A microprocessor (44) is employed to measure and analyze the amplitude and contour of this signal in a direction toward the loin until it reaches a fixed point that is a prescribed percentage of the peak value of the amplitude of this signal, the magnitude of which depends on the type of animal under measurement. The value derived in this manner is an accurate measurement of the depth of overlaying backfat and is automatically displayed in digital form on a screen (46).
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