What are the two adjustable variables contained in an On-Off pressure controller?

The correct answer highlights the two main adjustable variables found in an On-Off pressure controller: pressure adjustment and differential adjustment.

In an On-Off pressure controller, the pressure adjustment allows the operator to set the desired pressure level at which the controller will activate or deactivate the system. This is key in maintaining the pressure within desired parameters, ensuring safe and efficient operation.

The differential adjustment, on the other hand, is essential for setting the difference between the cut-in pressure (the pressure at which the controller turns the system on) and the cut-out pressure (the pressure at which the controller turns the system off). By controlling this differential, the system can prevent unnecessary cycling, saving energy and prolonging equipment life.

In contrast, options mentioning flow adjustment, fuel adjustment, or temperature adjustment are not relevant to the function of an On-Off pressure controller as they do not pertain to the control of pressure directly and thus do not accurately represent the key functionalities of this type of controller.