PASCO TD-8564 THERMAL EFFICIENCY APPARATUS - Manual (Page 13)

012-05443A Thermal Efficiency Apparatus
9
Experiment 1: Heat Engine and Temperature Difference
EQUIPMENT NEEDED:
— Thermal Efficiency Apparatus — DC power supply capable of 2.5 A at 12 V
— ohmmeter — ammeter (up to 3 A)
— patch cords — 2 voltmeters
— 3 kg (7 lbs) ice and a bucket for the ice-
water bath
Introduction
In this experiment the user will determine the actual efficiency and the Carnot efficiency of the
heat engine as a function of the operating temperatures.
Setup
➀ Prepare the ice-water bath and immerse both rubber tubes from the Thermal Efficiency Appara-
tus into the bath (Figure 4).
➁ Plug the 9V transformer into the wall socket and into the pump on the Thermal Efficiency
Apparatus. You should now hear the pump running and water should be coming out of the
rubber hose marked “out”.
➂
Plug the ohmmeter into the thermistor terminals.
➃
Connect a DC power supply and a voltmeter and ammeter to the heater block terminals. Adjust
the voltage to about 11 V.
➤ NOTE: This is just a suggested value chosen to make the hot temperature nearly at the
maximum allowed. Any voltage less than 12 V is suitable. The Thermal Efficiency
Apparatus should not be run for more than 5 minutes with the hot side above 80°C. A
thermal switch will automatically shut off the current to the heater block if it exceeds
93°C to prevent damage to the device.
Ω
V
V
A
Power
Supply
0.5
Ω
1
Ω
2
Ω
Figure 1.1