초록 ▼

A device is provided for detecting the ullage level and flow in a vessel by detecting the presence of a solid or liquid material in proximity to a microwave detector. The device may be mounted to the side of the vessel or suspended inside the vessel so as to bring the microwave sensor into proximity

A device is provided for detecting the ullage level and flow in a vessel by detecting the presence of a solid or liquid material in proximity to a microwave detector. The device may be mounted to the side of the vessel or suspended inside the vessel so as to bring the microwave sensor into proximity with the surface of the contents of the vessel. A microwave bridge circuit may be used to detect a change in either the amplitude or phase of a signal reflected by the material within the vessel compared to a reference signal tuned to either the presence or absence of the anticipated solid or liquid material. In one embodiment, the reflected material signal is compared to the signal from a sample chamber containing the material to be detected. The device can reliably detect the level of multiple interfaces for various materials having distinct electric or magnetic properties.

대표청구항 ▼

A sensor for detecting the movement characteristics of material in a container or conduit, comprising: microwave oscillator means for generating a constant propagated microwave in a frequency range of from 1 to 20 gigahertz; microwave bridge circuit means for dividing microwave into a measurement mi

A sensor for detecting the movement characteristics of material in a container or conduit, comprising: microwave oscillator means for generating a constant propagated microwave in a frequency range of from 1 to 20 gigahertz; microwave bridge circuit means for dividing microwave into a measurement microwave and a reference microwave; first guide means for injecting the measurement microwave through a portion of the container substantially transparent to the propagated microwave frequency and for returning a reflected measurement microwave to the microwave bridge circuit means indicative of the reflection coefficient at the boundary layer of the transparent portion, the coefficient being significantly altered by one of the presence, the absence and the movement of the material at the level of the first guide means; second guide means for transmitting the reference wave from the microwave bridge circuit means and for returning a reflected reference wave to the microwave bridge circuit means; reference wave altering means for altering the reflected reference wave to correspond in amplitude and phase to the reflected measurement microwave as altered by the presence, absence or movement of the material at the level of the first guide means; the microwave bridge circuit means receiving the reflected measurement and reference waves and producing a differentiation signal indicative of a difference in magnitude and phase between the waves; detector means for generating an output indicative of the magnitude of the differentiation signal; and comparator means for comparing the magnitude of the detector means output to a preselected signal magnitude and for providing an actuation signal indicative of the presence, absence or movement of the material at the level of the first guide means.