Figure 1-6. Temperature comparison of the Fisher and Bunsen burners.
NOTE:
Numbers denote degrees Fahrenheit.)
1-8.
REGULATION OF HEAT
a. Many medicinal products are affected by the application of excessive heat.
Further, it is advantageous to be able to control the level of heat you are applying to a
particular substance or product. Baths of various types are used to control and
distribute heat.
b. Water baths are probably the most frequently used means to regulate and
control heat. Water baths consist of copper or Monel metal containers equipped with a
lid from a number of concentric rings of the same material. The concentric rings can be
removed or added to permit adjustments for various sizes of flasks or beakers. A short
horizontal tube is provided near the top of the bath for the escape of steam. Since both
the water in the bath and the steam arising from it are under atmospheric pressure, the
highest temperature obtainable is 100 C. If the heating is to be continued for a long
period, the water lost by evaporation must be replaced.
MD0809
1-15