How many mercury switches does a strainer type CHT system have?

In a strainer-type Collection, Holding, and Transfer (CHT) system, it is designed to operate with one mercury switch. This switch is primarily used to monitor the level of the fluid in the system, ensuring that it remains within designated parameters for safe operation. The presence of just one mercury switch simplifies the system's design and functionality, allowing for efficient response to level changes without the complexity that would arise from having multiple switches. Thus, one mercury switch serves to effectively manage the necessary operations of the strainer-type CHT system.