What feature allows a solid state liquid level control to function with only one probe?

The feature that allows a solid state liquid level control to function with only one probe is the built-in time delay. This functionality is crucial in applications where a single probe is used to measure the level of liquid, as it helps prevent false readings caused by temporary fluctuations in liquid levels, such as splashing or turbulence.

The time delay allows the system to ignore transient signals that could lead to incorrect activation or deactivation of the control system. By introducing a delay, the controller can discern between actual changes in liquid level and temporary disturbances, ensuring more accurate operation. This capability is essential for maintaining the desired functionality while utilizing a single probe setup, which simplifies installation and reduces costs.

In contrast, other features like auto-reset functions, overload protection, and voltage regulation serve different purposes, such as ensuring system safety and reliability but do not directly enable the use of a single probe in liquid level control applications.