Liquid level control systems

A method, comprising:

• a) through operation of at least one control component, determining that a pressure sensor component in fluid communication with a tube extending in a reservoir to an air bell in the reservoir indicates a possible decrease in a liquid level in the reservoir to at least a predetermined level;
• b) through operation of the at least one control component responsive to (a), causing a compressor to pump gas through the tube to the air bell for a predetermined amount of time;
• c) through operation of the at least one control component responsive to (a), after (b) determining that the pressure sensor component indicates that the liquid level exceeds a predetermined threshold;
• d) through operation of the at least one control component responsive to (c), setting a flag in a memory;
• e) through operation of the at least one control component, after (d) determining that the pressure sensor component indicates a possible decrease in the liquid level to at least the predetermined level in (a);
• f) through operation of the at least one control component responsive to (e) and the flag, causing at least one alarm output device to output an alarm signal.

A computer-readable medium comprising instructions that, when executed by at least one processor, perform the following acts:

• a) determining that a pressure sensor component in fluid communication with a tube extending in a reservoir to an air bell in the reservoir indicates a possible decrease in a liquid level in the reservoir to at least a predetermined level;
• b) responsive to (a), causing a compressor to pump gas through the tube to the air bell for a predetermined amount of time;
• c) responsive to (a), after (b) determining that the pressure sensor component indicates that the liquid level exceeds a predetermined threshold;
• d) responsive to (c), setting a flag in a memory;
• e) after (d), determining that the pressure sensor component indicates a possible decrease in the liquid level to at least the predetermined level in (a);
• f) responsive to (e) and the flag, causing at least one alarm output device to output an alarm signal.