What Is the Difference Between Water Bath and Oil Bath?
Both Water bath and oil bath adopt electric heating to maintain constant temperature. They can be used for sample distillation, drying, concentration, impregnation and other tests, and widely used in petrochemical, metallurgy, medical and health, scientific research, environmental protection and other fields. Are they different?
Yes, they have the following difference.
1.The heating medium is different: the water bath adopts water, while the oil bath adopts oil. Generally we adopt oil such as methyl silicone oil or dimethyl silicone oil as the heating medium.
2.The temperature range is different: the temperature range of water bath is room temperature to 100 ℃（ 212 ℉) while the temperature range of oil bath is room temperature to 300 ℃（ 572 ℉).
3.The material and parts are different: generally speaking, the highest working temperature of oil bath is higher than the water bath, so all the parts must have better heat resistance. The main differences are the following three aspects:
(1). Outer wall thickness: oil bath adopts thickened SUS 304 plate while the ordinary SUS 304 plate is enough for water bath.
(2). Different heating pipes: the heating pipes of oil bath is thicker, so high power.
(3). Different temperature controller: the oil bath temperature controller has a wider control parameter.
4.Differet prices: the oil bath is more expensive than the water bath because the cost is higher.
5.The oil bath can be used as water bath, but the water bath cannot be used as oil bath.
6.Comparison of how to use water bath and oil bath:
I. Usage of water bath
(1) Close the drain valve and fill the water bath with clean water (pure water) to an appropriate depth, generally it will not exceed 2/3 of the capacity of the water bath.
(2) Connect the power supply and make sure the equipment is properly grounded.
(3) Turn on equipment, adjust the temperature control button to the set temperature.
Safety precaution:
(1) Remember that the water level must not be lower than the electric heating pipe, otherwise the electric heating pipe will be burnt out immediately.
(2) The inside of the controller shall not be affected by moisture to prevent electric leakage and damage to the controller.
(3) Pay attention to whether the water tank has leakage at any time during use.
II. Usage of oil bath
(1) When using the oil bath, you must first add oil to the oil bath tank, and then connect to the power supply. The digital temperature controller displays the actual measured temperature, adjust the knob switch.
(2) At the same time, observe the reading to the required temperature value. When the set temperature value exceeds the oil temperature, the heating indicator light is on, indicating that the heater has begun to work.
(3) When the oil temperature reaches the required temperature, the constant temperature indicator light is on and the heating indicator light is off.
(4) It should be noted that the oil in the pot cannot make the electric heating tube leak out of the oil surface, so as to avoid burning the electric heating tube and causing electric leakage.
Safety precaution:
(1) When injecting liquid into the oil bath, the liquid level should be controlled to prevent excessive overflow. In summer, the indoor and outdoor temperatures differ greatly. When the experimental temperature reaches 300 ℃, the liquid level should be controlled at about 80% of the volume.
(2) It is forbidden to use oil with high flammability and volatility. The oil used should be determined according to the temperature and experimental requirements. Glycerol is used for low temperature and cottonseed oil is used for high temperature.
(3) Do not use the oil bath in places with poor ventilation. Keep away from fire sources and places prone to sparks to avoid fire.
(4) It is forbidden to burn in air without oil, which will cause electric leakage, fire and burn out the heating pipe. It is forbidden to operate with wet hands, which may cause electric leakage and electric shock. The power supply must use a grounding plug.