This book helps in describing boy's calorimeter experiment and the calculations involved.

2. BOYS CALORIMETER
Boy’s Calorimeter is used to determine calorefic value of gaseous
and volatile liquid fuel.

3. PRINCIPLE
A known amount of fuel is burnt in excess of oxygen and
the heat liberated by combustion of fuel is transferred to a
known quantity of water.
Heat liberated by fuel = heat gained by H2O

4. APPARATUS
 GAS Barrier
 Two rotameter (Flowmeter)
 Pressure gauge
 Combustion chambers/chimney with copper lubing
coil/outside & inside
 Insulated containers
 Two thermometers
 Two collecting containers

5. Measurement
1. Volume of gas burnt at constant temperature and
pressure in time t.
2. Amount of water collected in time t.
3. Amount of steam condensed in time t.

6. Calculation
When steady state is established during the experiment,
the following measurement are made.
V = Vol. of gas burnt at constant temperature and pressure
in a certain time t.
W = The amount of water passing through the cell in time t.
T2-T1 = Steady rise in temp.
m = mass of water condensed from steam during time t.
L = Higher calorific value of fuel.

7. Calculation cont.

8. NET & GROSS CALORIFIC VALUE
The net calorific value (Hu or Hi) is the energy released
during a full combustion when the five gas is cooled back to
the reference temperature at a constant pressure. In this
case the H2O vapour produced during combustion remain
in gaseous form. The net calorific value therefore only
specifies the quantity of sensible heat in the flue gases and
is directly related to temperature and not the quantity of
condensation heat bound in the H2O vapour.
Gross calorific value (H0 or Hs) is the energy released
during a complete combustion when the flue gas is cooled
back to the reference temperature at a constant press and
entire quantity of H2O produced is condensed.
The gross calorific value therefore also contains the
condensation heat, also referred to as content heat.