System and methods for field monitoring of stationary assets

A method for determining a fill level of a container, the method comprising:

• disposing a first pressure sensor near a bottom of the container;
• attaching an enclosure on an outer surface of the container, wherein a second pressure sensor is disposed in the enclosure,
• wherein the first pressure sensor is connected to the enclosure by a cable passing through a hatch of the container;
• closing the hatch of the container to isolate the first pressure sensor inside the container from the second pressure sensor outside the container;
• measuring, with the first pressure sensor, a tank pressure near the bottom of the container;
• measuring, with the second pressure sensor, an atmospheric pressure at an outside surface of the container;
• subtracting the atmospheric pressure from the tank pressure to determine a net pressure;
• calculating the fill level of the container using the net pressure.

A system for monitoring a fill level of a container, the system comprising:

• an environmentally-isolated enclosure;
• and
• a processor disposed within the enclosure,
• a wireless transceiver disposed within the enclosure,
• a cable connected to the processor and extends out of the enclosure,
• a first pressure sensor attached to an end of the cable that is distal from the enclosure, and
• a second pressure sensor connected to the processor and disposed within the enclosure;
• and
• a solar panel disposed on an outer surface the enclosure that powers a battery connected to the processor, first pressure sensor, second pressure sensor, and the wireless communication unit;
• wherein the enclosure is mounted to an outer surface of the container,
• wherein the cable is inserted into the container via an opening such that the first pressure sensor is disposed at a bottom of the container,
• wherein the first pressure sensor measures a pressure at the bottom of the container,
• wherein the second pressure sensor measures a pressure outside of the container,
• wherein the processor is configured to cross-correlate readings from the first pressure sensor and the second pressure sensor to determine a net pressure for use in calculating the fill level of the container, and
• wherein the wireless transceiver is configured to wireless relay data from the processor.