Patent ID: 8220584
Filing Date: 2012-07-17
Classification: G01F

Abstract:
1. A hybrid measurement instrument comprising: a sensor circuit comprising a drive circuit for transmitting a pulse signal at a target of interest and a receive circuit receiving reflected echoes of the pulse signal and developing an analog signal representative of the reflected echoes; an analog processing circuit operatively coupled to the sensor circuit for receiving the analog signal and comprising a gate for selectively transferring the analog signal to a comparator that compares the gated analog signal to a select threshold level to develop a data signal representative of location of the target of interest; and a programmed digital processing circuit operatively coupled to the sensor circuit and the analog processing circuit, and comprising a measurement module to control the drive circuit and evaluate the data signal to determine material location, and an echo processing module to periodically evaluate a digital representation of the analog signal to determine an expected window time and expected amplitude of the reflected echo representing the target of interest and developing a gate control signal to control the gate based on the expected window time and developing the select threshold level based on the expected amplitude.