The dials on toasters typically control the time the toast cooks rather than the temperature. The toaster's heating elements are designed to reach a certain temperature, and they remain at that temperature during the toasting process.
When you turn the dial on a toaster, you are adjusting the duration of toasting. The higher the dial setting, the longer the bread stays inside the toaster, and the darker or toastier it becomes. Similarly, lowering the dial setting results in shorter toasting times and lighter toast.
Toasters do not have advanced temperature control like ovens. Instead, they work on a simple timing mechanism, whereby the toast is exposed to the same constant temperature of the heating elements for a set amount of time.
Keep in mind that the actual toasting time may vary slightly from toaster to toaster due to differences in design, insulation, and heating element power. Additionally, factors like the initial temperature of the bread and the ambient temperature in the room can also affect the toasting time.
It's essential to monitor the toast while it's toasting to achieve the desired level of doneness. If you prefer lighter toast, you can interrupt the toasting process by popping the bread up before the timer ends. Conversely, for darker toast, you can leave the bread in for an extra moment after the initial toasting cycle.