Principles of Laboratory Hot Air Oven

Principles of Laboratory Hot Air Oven

Hot air oven is widely used in pharmaceutical laboratories and other material testing laboratories. With the rising awareness about dry sterilisation process, the demand for laboratory hot air oven is also rising. In this post, we will discuss the fundamentals of the machine.

Working principle

The working principle is based on fine gravity air convection in an electrically heated chamber. The machine is equipped with various components to ensure the uniform heating throughout the chamber. Two jacket design, automatic control unit, PID controlled, PT 100 sensors, temperature preset, etc. allows the machine to work efficiently and return to normal temperature when the test process is over. It is designed to simplify the process of dry sterilisation and pre-treatment of different materials like rubber, plastic, etc. 

Inside the chamber the air flows in a forced circulation manner, this allows the appropriate heat distribution inside the chamber. As the air inside the chamber becomes hot, it becomes lighter and moves in the upward direction. As it reaches the top, the fan inside the chamber pushes it back to the bottom. This creates a circular motion inside the cabinet and makes a consistent circular flow of the air. With this process, eventually, the optimum temperature is achieved. 

It is always to be taken care that articles kept for sterilisation should not be taken out immediately. Let the oven comes to a normal temperature and then the articles are taken out. 

Advantages of Using Laboratory Hot Air Oven

Not all articles are suitable for wet sterilisation. It can be successfully used for materials like powder and oil which otherwise get spoiled during wet sterilisation.

The articles do not need to be dismantled as the whole article is exposed to the high temperature for a good time. 

Even metal equipment are safe with dry sterilisation, which otherwise gets corroded in wet sterilisation.

Dry sterilisation is safe for the operator. Unlike autoclaving, that uses a pressurised method for wet process. 

Precautions to be taken

It is not advised to keep the article directly on the floor and it is hotter in comparison to the chamber temperature. Perforated shelves are meant for keeping the articles that are to be sterilised. 

For the uniform heat distribution, there has to be space between the articles and ample of distance from the walls. 

The glass apparatus should be wrapped with clean cloth 

Do not load the chamber more than the prescribed limit.