A bi-metal strip in a sequencer timer serves what purpose?

The function of a bi-metal strip in a sequencer timer is crucial for the operation of heating systems, particularly in the context of electric heat. When the bi-metal strip is heated, it bends due to the differential expansion of its two metals. This bending action is utilized to open or close electrical contact points, thereby controlling the timing of electrical circuits in the heater.

As the bi-metal strip reaches a certain temperature, it will either make or break the connection, allowing for sequential operation of heating elements. This is particularly important in systems where you want to avoid overloading the electrical system by staggering the operation of different elements. Closing contact points helps ensure that the heating elements turn on and off in a controlled manner, maintaining efficiency and safety in the heating process.

The other options focus on different functionalities that are not performed by a bi-metal strip in this context. Measuring temperature is not the strip's primary role; rather, it responds to temperature changes by bending. Regulating airflow is related to ductwork and fans, rather than the electric control mechanisms of heating elements. Monitoring voltage involves electrical measurement devices separate from the mechanical actions of a sequencer timer's bi-metal strip.