The devices used to produce heat are among the most frequent electrical equipment seen in a typical laboratory. In many cases, heat is required to achieve a reaction or separation. Sometimes, it may be required to enhance mixing when using a magnetic stirrer such as the 2mag.
The heating devices are designed to convert electrical current into heat energy. They include:
- Hot plates
- Hot air guns
- Hot baths (air, oil, and water)
- Hot-tube furnaces
- Heating mantles
When temperatures of 100 °C or less are necessary, steam-heated equipment is often preferable over electrically heated devices. They may be left unattended since they do not provide a shock or spark danger, and their temperature will never surpass 100 °C.
Note: Utilize steam produced by laboratory-specific units. Contaminants in the steam produced for general facility usage may interfere with laboratory operations.
Proper and Safe Use of Heating Devices
- Bare wires should not be utilized in resistance devices to heat oil baths. If a heating device gets worn or broken to the point that the heating element is exposed, discard it or repair it before using it again.
- Control and restrict the input voltage to some proportion of the entire line voltage, typically 110 V, by using laboratory heating devices that have a variable autotransformer.
- When using an electrical heating device, either a temperature controller or a temperature-sensing device must be used to switch off the power if the temperature of the heating device exceeds a predetermined limit.
- Control devices are also available that will cut power if the flow of cooling water through a condenser is interrupted due to a loss of water pressure or a loosening of the water supply line to a condenser.
- Fail-safe devices, which may be bought or built, can prevent more catastrophic issues like fires or explosions from occurring if the temperature of a reaction rises significantly due to a change in line voltage, the unintentional loss of solvent, or a lack of cooling.