초록 ▼

A magnetostrictive liquid level probe in a double-walled liquid container develops liquid level data and external sensors in the space between the walls respond to the presence of liquid leaked into the space from inside or outside the container. Other sensors external of the liquid level probe may

A magnetostrictive liquid level probe in a double-walled liquid container develops liquid level data and external sensors in the space between the walls respond to the presence of liquid leaked into the space from inside or outside the container. Other sensors external of the liquid level probe may sense other conditions. The probe electronics determines binary states of the external sensors and digitally encodes the states for inclusion in data transmission of the liquid level information to a remote controller via a two-wire transmission line. One embodiment develops pulses spaced as a digital function of the sensor states and includes liquid level data between the pulses for transmission. The pulse space is measured at the remote controller and decoded to determine the external sensor states, while the liquid level data is analyzed to determine the contents of the container.

대표청구항 ▼

[ What is claimed is:] [1.] In a system having a liquid storage container having a liquid level probe adapted to measure a liquid level in the storage container and to generate an output signal representative of the liquid level along with sensors adapted to sense conditions of the storage container

[ What is claimed is:] [1.] In a system having a liquid storage container having a liquid level probe adapted to measure a liquid level in the storage container and to generate an output signal representative of the liquid level along with sensors adapted to sense conditions of the storage container independent of said probe and to produce output signals representative of said sensed conditions, the method of acquiring information at a remote location of the liquid level in the container and the conditions independent of the probe comprising the steps of:measuring a liquid level in said liquid storage container with said liquid level probe;generating a measured liquid level output signal;sensing a condition independent of said probe with said sensors, the sensors generating a sensed condition signal, the sensing step further including the step of:sensing a plurality of conditions independent of said probe to generate a plurality of sensed condition signals each representative of a particular sensed condition independent of the probe;combining said measured liquid level output signal and the sensed condition signal to produce a combined signal, the step of combining said signals to produce a combined signal further including the steps of:producing a series of pulses uniquely spaced according to the states of the plurality of sensed condition signals; andinputting the measured liquid level signal between adjacent pulses of the series of uniquely spaced pulses; andtransmitting the combined signal over a two wire transmission line to the remote location.