Thermodynamics: Mechanical Equivalent Of Heat Apparatus MODEL TH 012

Sci-tech Mechanical Equivalent of Heat Apparatus Model TH 012 has been designed to enable students to
study and measure the mechanical work dissipated and the heat energy generated to determine experimentally
the mechanical equivalent of heat. Comparisons can be made with the established value of this constant and
errors can be analyzed.

Item Description

The apparatus consists of a rotating drum calorimeter containing a fixed quantity of water in it. The calorimeter
can be rotated using a pulley and a toothed belt driven by a variable speed DC motor. Mechanical energy is
dissipated by friction between the rotating drum calorimeter and the brake band wound around it. The
mechanical energy dissipated is measured using the spring dynamometer- weight hanger system. The
equivalent heat energy generated because of the dissipation of mechanical energy is measured by the increase
in temperature of the calorimeter and the water contained in it. Thus, the mechanical equivalent of heat can be
determined. The apparatus is compact, rugged and robust and is mounted on a moveable platform. This apparatus can also be used to determine the thermal capacity of the calorimeter or the specific heat of the
calorimeter material by assuming the equivalence of the mechanical work and the heat energy

Technical Specifications

1. Variable speed DC motor with speed regulation. 0.5 KW, 500 RPM.
2. Rotating Drum Calorimeter driven by pulley and toothed belt, Internal diameter 150mm, length 150mm and made of copper.
3. Dynamometer, brake band with mass hanger and spring balance, capacity = 10 kg.
4. Mercury thermometer, 0 –600 range, accuracy = 0.10.
5. Mechanical revolutions counter with zero setting.
6. Standard weights, 1 kg. (5 Nos.), 5 kg. (1 No.)
7. Stop watch, digital and 1/100 sec. resolution.
8. Power supply and control panel.

Services Required Electrical Supply, 220-240 V Single-phase.