Among minor difficulties of the method may be mentioned the uncertainty of the thermal capacity of the calorimeter and stirrer, and of the immersed portion of the thermometer.
The surface of the calorimeter and the enclosure should be permanently blackened so as to increase the loss of heat by radiation as much as possible, as compared with the losses by convection and conduction, which are less regular.
The Water Equivalent Of The Calorimeter Is Immaterial, Since There Is No Appreciable Change Of Temperature.
The Current Through A Platinoid Resistance Of About 31 Ohms In A Calorimeter Containing 1500 Grammes Of Water Was Regulated So That The Potential Difference On Its Terminals Was Equal To That Of Twenty Board Of Trade Clark Cells In Series.
The same type of calorimeter is used in determining the heat of solution of a solid or liquid in water.
The calorimeter used for solutions is usually cylindrical, and made of glass or a metal which is not, attacked by the reacting substances.
A continuous flow calorimeter has been used by the writer for measuring quantities of heat conveyed by conduction (see Conduction Of Heat), and also for determining the variation of the specific heat of water.
This is another objection to Rumford's method of cooling the calorimeter below the surrounding temperature before starting.
A metal vessel was placed in a calorimeter and air forced into it, the amount of energy expended in compressing the air being measured.
The present writer has found that very good results may be obtained by enclosing the calorimeter in a vacuum jacket (as illustrated in fig.