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公开(公告)号：US5861755A
公开(公告)日：1999-01-19
申请号：US552456
申请日：1995-11-06
CPC分类号： G01F1/74 , G01F1/64 , G01N27/221 , G01N27/226
摘要： A quality and/or flow meter employs a capacitance probe assembly for measuring the dielectric constant of flow stream, particularly a two-phase flow stream including liquid and gas components. The dielectric constant of the flow stream varies depending upon the volume ratios of its liquid and gas components, and capacitance measurements can therefore be employed to calculate the quality of the flow, which is defined as the volume ratio of liquid in the flow to the total volume ratio of gas and liquid in the flow. By using two spaced capacitance sensors, and cross-correlating the time varying capacitance values of each, the velocity of the flow stream can also be determined. A microcontroller-based processing circuit is employed to measure the capacitance of the probe sensors. The circuit employs high speed timer and counter circuits to provide a high resolution measurement of the time interval required to charge each capacitor in the probe assembly. In this manner, a high resolution, noise resistant, digital representation of each of capacitance value is obtained without the need for a high resolution A/D converter, or a high frequency oscillator circuit. One embodiment of the probe assembly employs a capacitor with two ground plates which provide symmetry to insure that accurate measurements are made thereby.
摘要翻译： 质量和/或流量计采用电容探针组件来测量流动流的介电常数，特别是包括液体和气体组分的两相流动流。 流量的介电常数根据其液体和气体组分的体积比而变化，因此可以采用电容测量来计算流量的质量，其定义为流体中液体与总量之间的体积比 气体和液体的流量体积比。 通过使用两个间隔的电容传感器，并且互相关联每个的时变电容值，也可以确定流动流的速度。 采用基于微处理器的处理电路来测量探头传感器的电容。 该电路使用高速定时器和计数器电路来提供对探针组件中每个电容器充电所需的时间间隔的高分辨率测量。 以这种方式，不需要高分辨率A / D转换器或高频振荡器电路就能获得每个电容值的高分辨率，抗噪声的数字表示。 探针组件的一个实施例采用具有两个接地板的电容器，其提供对称性以确保由此进行准确的测量。
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公开(公告)号：US5979239A
公开(公告)日：1999-11-09
申请号：US845900
申请日：1997-04-28
摘要： An imaging system is described which can be used to either passively search for sources of ultrasonics or as an active phase imaging system, which can image fires, gas leaks, or air temperature gradients. This system uses an array of ultrasonic receivers coupled to an ultrasound collector or lens to provide an electronic image of the ultrasound intensity in a selected angular region of space. A system is described which includes a video camera to provide a visual reference to a region being examined for ultrasonic signals.
摘要翻译： 描述了一种成像系统，其可用于被动搜索超声波源或作为可以成像火灾，气体泄漏或空气温度梯度的主动相位成像系统。 该系统使用耦合到超声收集器或透镜的超声波接收器的阵列来提供在选定的空间角度区域中的超声强度的电子图像。 描述了一种系统，其包括摄像机，以向被检查的超声信号区域提供视觉参考。
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公开(公告)号：US5710377A
公开(公告)日：1998-01-20
申请号：US540616
申请日：1995-10-17
摘要： A system for detecting ultrasonic vibrations, such as those generated by a small leak in a pressurized container, vessel, pipe, or the like, comprises an ultrasonic transducer assembly and a processing circuit for converting transducer signals into an audio frequency range signal. The audio frequency range signal can be used to drive a pair of headphones worn by an operator. A diode rectifier based mixing circuit provides a simple, inexpensive way to mix the transducer signal with a square wave signal generated by an oscillator, and thereby generate the audio frequency signal. The sensitivity of the system is greatly increased through proper selection and matching of the system components, and the use of noise rejection filters and elements. In addition, a parabolic collecting horn is preferably employed which is mounted on the transducer assembly housing. The collecting horn increases sensitivity of the system by amplifying the received signals, and provides directionality which facilitates easier location of an ultrasonic vibration source.
摘要翻译： 用于检测超声波振动的系统，例如由加压容器，容器，管等中的小泄漏产生的超声波振动的系统，包括超声换能器组件和用于将换能器信号转换成音频频率范围信号的处理电路。 音频范围信号可用于驱动由操作者佩戴的一对耳机。 基于二极管整流器的混合电路提供了一种简单，便宜的方法来将换能器信号与由振荡器产生的方波信号混合，从而产生音频信号。 通过系统组件的适当选择和匹配以及使用噪声抑制滤波器和元件，可以大大提高系统的灵敏度。 此外，优选地使用安装在换能器组件壳体上的抛物线收集喇叭。 收集喇叭通过放大接收到的信号来增加系统的灵敏度，并且提供便于更容易定位超声波振动源的方向性。
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