1. RANI LAKSHMI BAI CENTRAL AGRICULTURAL UNIVERSITY,
JHANSI
TOPIC: WATER BATH AND SAND BATH
Course:Basic concept in laboratory techniques PGS 504 1(0+1)
SUBMITTED TO,
Dr. Abhishek kumar
Dept. of Biotechnology
RLBCAU, Jhansi.
3. O A water bath is a device that maintains
water at a constant temperature.
O It allows the heating of small amounts of
fluids over a period of time without
changing the concentration of constituents
by evaporation.
O It is also used when several tubes are to
be handled while maintaining the
temperature of the contents,e.g., in
coagulation tests.
4. O Water bath is an instrument used for
maintaining a uniform temperature
throughout the fluid contained in a glass
container by keeping it in pre–heated
water.
O It also prevents excessive evaporation of
the fluid being heated.
5. Components
O It is made up of insulated metal, usually
stainless steel or of heat resistant glass
with or without an insulated lid.
O An electric element to heat the water
contained in the trough.
O A propeller or stirrer to circulate the water
in the trough in order to maintain a
uniform
trough.
temperature throughout the
6. O A thermometer to check the temperature.
This may be in-built or placed separately
in the trough.
O A thermostat to maintain the temperature
at a constant level.
7. Water Bath Controls:
Temperature Control:
O 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.
8. Safety control
O Most water baths have a second control called
the safety. This control is set at the maximum
temperature the water bath should attain.
O It is usually set just above the temperature
control. Often an indicator light is associated with
the safety control.
O 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
temperature setting is higher.
even when the
9. O 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.
10.
11.
12. Operating procedure
O Fill it with clean (preferably distilled) water
to a desired level and then switch it on.
O Set the thermostat to desired temperature
and allow the water to warm to that
temperature.
O Check the
thermometer.
temperature from the
13. Precautions and
maintenance
O Clean from inside and change the water
daily.
O This will prevent encrustation of stirrer,
heat probe and thermostat with salts
contained in raw water.
O It will also prevent the growth of fungi and
algae.
14. O Keep the lid closed when not in use to
prevent evaporation of water.
O Periodically check and counter-check the
water temperature with internal as well as
with an external thermometer.
O The thermometer should be placed in
such a way that it is away from the
heating element and the walls.
15. Specifications of a water bath for district
laboratories
O Unstirred with hydraulic
electronic temperature control.
thermostat or
O Operating over a temperature range from
ambient to 60 °C or above.
O Having a 4 litre capacity.
O Fitted with a thermometer.
O Supplied with a lid.
16. Uses
O It provide Indirect heat.
O Used for warming blood bag blood.
O Used for incubation of test such as PT,
APTT and Coombs test.
18. • A sand bath is a common piece of laboratory equipment
made from a container filled with heated sand.
• It is used to provide even heating for another container,
most often during chemical reaction.
• A sand bath is most commonly used in conjunction with
a hot plate or heating mantle. A beaker is filled with sand
and placed on the plate.
• The reaction vessel is then partially covered by sand.
The sand then conduct heat from the plate to all sides
of the reaction vessel.
19. Sand bath differ from water bath in which sand
is replaced with water
