The instruction to "turn part 10 then to desired time" on most conventional toaster ovens refers to the timer knob or dial located on the appliance. Part 10 likely represents the timer control knob.
The reason for this type of instruction is to provide a user-friendly and intuitive way to set the cooking time for various types of food. Here's why toaster ovens (and many other kitchen appliances) use this method:
Simplicity: The "turn and set" method is straightforward and easy to understand for users of all ages. It doesn't require any complex programming or digital interfaces, making it accessible to anyone.
Versatility: Toaster ovens can be used for a wide range of cooking tasks, from toasting bread and bagels to baking, roasting, and broiling. Using a timer knob allows users to set precise cooking times for different recipes without confusion.
Reliability: Mechanical timer knobs are generally more reliable and durable than electronic controls. They are less prone to malfunctions and are often easier to repair or replace if needed.
Cost-effective: Mechanical timer knobs are cheaper to manufacture than electronic displays and controls, contributing to overall cost savings for the manufacturer and, potentially, the consumer.
User preference: Some people simply prefer the tactile feel of turning a physical knob over pushing buttons on a digital interface.
Though digital and electronic controls have become increasingly popular in modern appliances, the "turn and set" method is a tried-and-true design that has been used for decades. It continues to be favored for its simplicity and ease of use.