Disclosed is a digital liquid level sensor based on a magnetoresistive sensor cross-point array, including: a plurality of TMR magnetic sensor chips; a microcontroller, a row decoder, and a column decoder, wherein the microcontroller is electrically connected to the row decoder and the column decoder, the TMR magnetic sensor chips include a plurality of MTJ elements, diodes are connected between each row of MTJ elements and a row lead or a column lead, the TMR magnetic sensor chips are addressed by means of data decoded by the row decoder and the column decoder and on the basis of the equation Address=m+[M×(n−1)], Address representing an address value, and m representing the value of a current row, and the microcontroller is used for scanning addresses of the TMR magnetic sensor chips for the address of an MTJ element in the highest active state, converting the address value into a liquid level value in a linear proportional relationship therewith, and transmitting the liquid level value to an output interface; and a permanent magnet and a protective tube. The power consumption of a sensor element is greatly minimized by powering only one sensor chip element each time.

Disclosed is a digital liquid level sensor based on a magnetoresistive sensor cross-point array, including: a plurality of TMR magnetic sensor chips; a microcontroller, a row decoder, and a column decoder, wherein the microcontroller is electrically connected to the row decoder and the column decoder, the TMR magnetic sensor chips include a plurality of MTJ elements, diodes are connected between each row of MTJ elements and a row lead or a column lead, the TMR magnetic sensor chips are addressed by means of data decoded by the row decoder and the column decoder and on the basis of the equation Address=m+[M×(n−1)], Address representing an address value, and m representing the value of a current row, and the microcontroller is used for scanning addresses of the TMR magnetic sensor chips for the address of an MTJ element in the highest active state, converting the address value into a liquid level value in a linear proportional relationship therewith, and transmitting the liquid level value to an output interface; and a permanent magnet and a protective tube. The power consumption of a sensor element is greatly minimized by powering only one sensor chip element each time.

A fuel storage system has a tank access chamber with improved monitoring, servicing and maintenance capabilities. In particular, the chamber includes a sump monitored by a liquid sensor whose proper function can be automatically checked remotely, e.g., via an electronic controller or remote manual operation. In cases where such a check indicates a need for physical inspection of the sump sensor, the present system provides for sensor removal and installation by service personnel from a location outside the tank access chamber. Thus, the present system facilitates regular inspection and routine or unplanned maintenance without the need for a person to physically enter the tank access chamber.

A fuel storage system has a tank access chamber with improved monitoring, servicing and maintenance capabilities. In particular, the chamber includes a sump monitored by a liquid sensor whose proper function can be automatically checked remotely, e.g., via an electronic controller or remote manual operation. In cases where such a check indicates a need for physical inspection of the sump sensor, the present system provides for sensor removal and installation by service personnel from a location outside the tank access chamber. Thus, the present system facilitates regular inspection and routine or unplanned maintenance without the need for a person to physically enter the tank access chamber.

Systems include a floating device disposed on a top of a column of drilling fluid in an annulus of a wellbore. The floating device includes a capsule. A transmitter or a reflector may be coupled to the capsule. The floating device may transmit signals to a surface region from the annulus or receive signals from the surface region and reflect at least a portion of the received signals. A receiver in the surface region receives transmitted signals or reflected signals from the floating device and determines a distance between the floating device and a reference point in the surface region. The distance indicates a level of the drilling fluid in the annulus.

Systems include a floating device disposed on a top of a column of drilling fluid in an annulus of a wellbore. The floating device includes a capsule. A transmitter or a reflector may be coupled to the capsule. The floating device may transmit signals to a surface region from the annulus or receive signals from the surface region and reflect at least a portion of the received signals. A receiver in the surface region receives transmitted signals or reflected signals from the floating device and determines a distance between the floating device and a reference point in the surface region. The distance indicates a level of the drilling fluid in the annulus.

Determining a level of a liquid in a container is described. In one aspect, a container includes a calibrant liquid used for calibrating a mass spectrometer. A conductive layer is placed to float upon the calibrant liquid, and a circuit board with electrodes is arranged around the container. A controller circuit then drives and measures various electrodes to first identify which two electrodes the level of the calibrant liquid is between, and then subsequently identify a more precise location for the level between the two electrodes.

The disclosed techniques enable the installation of a level sensor capable of continuously detecting a level of fluid in a vessel or tank and capable of being integrated in a larger control system. Advantageously, sensor head of the disclosed level sensor can be installed on existing installations with an existing displacer or float and an existing member or rod. The disclosed techniques thus enable process plants to easily and affordably replace pneumatic level sensors with a more environmentally friendly option.

The disclosed techniques enable the installation of a level sensor capable of continuously detecting a level of fluid in a vessel or tank and capable of being integrated in a larger control system. Advantageously, sensor head of the disclosed level sensor can be installed on existing installations with an existing displacer or float and an existing member or rod. The disclosed techniques thus enable process plants to easily and affordably replace pneumatic level sensors with a more environmentally friendly option.

Systems include a floating device disposed on a top of a column of drilling fluid in an annulus of a wellbore. The floating device includes a capsule. A transmitter or a reflector may be coupled to the capsule. The floating device may transmit signals to a surface region from the annulus or receive signals from the surface region and reflect at least a portion of the received signals. A receiver in the surface region receives transmitted signals or reflected signals from the floating device and determines a distance between the floating device and a reference point in the surface region. The distance indicates a level of the drilling fluid in the annulus.