Hot air ovens are electrical devices which use dry heat to sterilize. They were originally developed by Pasteur. Generally, they can be operated from 50 to 300 °C, using a thermostat to control the temperature.They are used as laboratory equipment for Packaged Drinking Water Plant.
Hot air oven Definition
- A hot air oven is a laboratory instrument that uses dry heat to sterilize laboratory equipment and other materials.
- That equipment cannot be wet or material that will not melt, catch fire, or change form when exposed to high temperatures are sterilized by using the dry heat sterilization method.
- Hot air oven also known as forced air circulating oven.
- Some examples of material which can not be sterilized by employing a hot air oven such as surgical dressings, rubber items, or plastic material.
Working Principle of Hot air oven/Hot air oven principle
Sterilization by dry heat is performed by conduction. The temperature is consumed by the surface of the objects, then moves towards the core of the object, coating by coating. The whole object will ultimately attain the temperature needed for sterilization to take place.
Dry heat causes most of the injury by oxidizing particles. The primary cell components are damaged and the organism dies. The temperature is kept for about an hour to eliminate the most ambitious of the resistant spores.
Hot air oven Parts and Functions
- External cabinet: The External cabinet is made of stainless sheets. It covers the inner chamber.
- Glass wool insulation: The space between the inner chamber and external cabinet is filled with Glass wool. It provides insulation to the hot air oven.
- Inner chamber: The inner chamber of the hot air oven is made of Stainless steel.
- Tubular air heaters: They help to generate heat within the inner chamber. Two Tubular air heaters are located on both sides of the inner chamber.
- Motor-driven blower: It helps in uniformly circulating the air within the chamber.
- Temperature sensor: It measures the temperature within the hot air oven and displays it on the controller screen.
- Tray slots: The inner wall of the chamber contains several try slots that hold the trays.
- PID temperature controller: It maintains the accurate temperature during the entire cycle. It also controls the temperature and also displays the temperature values.
- Load indicator: it indicates the hot air oven is overloaded.
- Mains on/off switch: It helps to turn on/ turn off the hot air oven.
- Safety thermostat: It is also known as an over-temperature protection device. It keeps your oven and specimen safe in case of controller malfunction.