Laboratory Equipment: Water Bath Description

A water bath is a device that maintains water at a constant temperature. It is used in the microbiological laboratory for incubations.

At the beginning of the lab period, you should check the water bath to see if it is turned on, set at the right temperature, and filled with water. Water baths should be filled with distilled water. If you are using the water bath for an experiment you should check the temperature frequently to make sure that the water bath is maintaining the proper temperature.

Water Bath Controls:

Temperature Control: All water baths have a control to set temperature. This control can be digital or a dial. Often there is an indicator light associated with this control. When the light is on the water bath is heating. When the water bath reaches the set temperature, it will cycle on and off to maintain constant temperature.

Safety Control: Most water baths have a second control called the safety. This control is set at the maximum temperature the water bath should attain. It is usually set just above the temperature control. Often an indicator light is associated with the safety control. If the water bath reaches the temperature that the safety control is set at, the light will go on. It will be impossible for the water bath to heat higher than the safety setting even when the temperature setting is higher. If your water bath stays a temperature lower than the temperature control setting, try increasing the safety control setting.

Shaking Control: Shaking water baths have additional controls for shaking. The shaking mechanism can be turned on or off. The speed of shaking can also be set. Cultures grown in liquid media are often shaken to allow constant mixing with air and oxygen with the culture. (Mouse over picture to see a large image of a shaking water bath)

Laboratory Equipment: Water Bath

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On to Water Bath Picture with Mouseover Parts