Define: The stirring heating plate or heated stirring heating plate has been developed to heat and mix fluids contained in laboratory receptacles such as flasks, test tubes and beakers. Temperature: Room Temperature up to approximately 500 °C. Rotation speed: From 60 RPM up to approximately 1200 RPM.

OPERATION PRINCIPLES: 1- The stirring heating plate has a flat surface . Some heating plates exclusively use radiation sources such as infrared (infrared light) for heating. 2- A heating element (an electrical resistor) . 3-A control system (on and off , temperature control, agitation control ) 4-Motor.

MAINTENANCE A-Cleaning Frequency: Monthly 1. Clean the equipment in a vertical position to avoid cleaning agents from reaching internal components. 2. Use a mild detergent. Apply to the external surfaces using a piece of cloth of similar texture to that of a handkerchief. 3. Verify that the equipment is completely dry before connecting it again B-Replacement of the ceramic surface (Whenever necessary) C-Replacement of fuses (Whenever necessary)

AUTOCLAVE

■Definition: The autoclave is a piece of equipment used for Sterilizing. The word sterilizing means the destruction or Elimination of all forms of life (microbial, Including spores) present in animate objects by means of physical, chemical or gaseous Procedures.  

  The main factors influencing steam sterilization are : Saturated steam Temperature Time

OPERATION PRINCIPLES: Autoclaves work by taking advantage of the thermodynamic properties of water, which can be considered as a pure substance. Note: In normal conditions (at sea level and pressure of 1 atmosphere) water (in liquid phase) boils and is converted into vapor (gaseous phase) at a 100 °C. If the pressure is reduced, it boils at a lower temperature. If the pressure rises, it boils at a greater temperature. Through the control of water vapour pressure, the autoclave can, in its sealed chamber, reach temperatures higher than 100°C; or inversely, by controlling the temperature, can achieve pressures greater than atmospheric pressure.

3. Sterilize contaminated material. PURPOSE OF THE AUTOCLAVE: The autoclave is equipment designed with the aim of reliably eliminating microorganisms, which would otherwise be present on objects used in diagnostic activities, in treatment or surveillance in health institutions (hospitals, laboratories). It is also widely used in the food processing and pharmaceutical industries. In the laboratory, materials and objects are sterilized for the following purposes: 1. To prepare materials for bacteriological cell cultures (test tubes, pipettes, Petri dishes, etc.) in order to avoid their contamination. 2. Prepare elements used for taking samples. (All must be in sterile conditions: needles, tubes, containers). 3. Sterilize contaminated material.

OPERATION OF THE AUTOCLAVE: 1. Turn the autoclave” ON. 2. Open the door of the autoclave. 3. Place the sterilization baskets or containers containing the previously prepared material (cleaned, washed, dried, classifi ed and packaged) into the sterilization chamber, according to the manufacturers’ recommended distribution instructions. 4. Close the door of the autoclave. 6. Select the required sterilization cycle depending on the type of objects or materials to be sterilized. 7. Open the door of the autoclave. 8. Unload the sterilized material. 9. Close the door once the sterilized material is unloaded to conserve the heat in the sterilization chamber and facilitate the next sterilization cycle.

Important component of Autoclave: 1. Safety valve. A device that impedes the vapor pressure from rising above a determined value. 2. Chamber manometer. A mechanical device that indicates the vapor pressure in the sterilization chamber. 3. Jacket manometer (pressure gauge). A mechanical device that indicates the vapour pressure inside the autoclave’s jacket. 4.Jacket. A space located around the sterilization chamber in which vapour circulates. Its purpose is to transfer heat to the chamber and lessen the formation of condensation 5. Autoclave door. A device which allows the sterilization chamber to be isolated from the outside environment

6. Door handle. A device which in some equipment, allows the operator to open and close the door 7. Sterilization chamber. The space where objects or materials to be sterilized are placed. 8. Thermometer. An instrument that indicates the temperature at which the sterilization processes in the autoclave chamber is done. 9. Drain. A collection line for the condensed liquid produced in the autoclave to exit.