Who can tell me what is the difference between the internal circulation and the external circulation of water bath, and what are their advantages? Thank you.

The external circulation water bath pots on the market are basically dual-purpose types of internal circulation and external circulation. External circulation is to pump the water in the tank to the circulation outlet through the circulating pump. The circulation outlet is usually connected to the water inlet of the temperature-controlled container through a hose, and the water outlet of the temperature-controlled container is also connected to the water inlet of the external circulation of the tank body through a hose, so as to realize the temperature control of the temperature-controlled container. What are the benefits of external circulation? Because the manufacturing process, temperature control range and water tank capacity are different, the appearance size of water bath is also different. Now let me give you an example: We use a rotary viscometer to measure the viscosity of silicone oil at 25 degrees. If the height of the water bath pot we bought is higher than that of the viscometer, and the beaker can't be directly measured in a constant temperature water tank, we have to use external circulation to control the temperature of silicone oil. The method comprise that following step: connecting the circulating water outlet of the wat bath pot to the water inlet of a beaker with a hollow interlayer through a hose, connecting the water outlet of the beaker with a hollow interlayer to the water inlet of the circulating water outside the water tank through a hose, and putting the silicone oil to be tested into the beaker. Simply put, if the temperature in the sink can't be controlled, it can be controlled by an external container circulating in the sink.